April 2016 Issue
Q I planted these shrubs about 4 years ago. They haven’t grown much, if at all. For two years now they, have looked like half of each bush is dying. It hasn’t gotten any worse but I’m not sure what to do. Any advice would be greatly appreciated. –Mary McCubbins, Shepherdsville
A Thanks for sending the pictures. They were helpful. There is definitely significant damage to your boxwoods. It is suspicious that the damage seems to be in the same location on both evergreens.
From the pictures, it appears that the rest of the plants are healthy. I suspect the die-back has to do with an herbicide drift. It could be some winter damage too because of the exposure, but we can rule out insect activity since it would be more evident throughout the plant. Stressed plants are more susceptible to insect damage so there may be some secondary issues.
Has this bed or nearby lawn been sprayed with any weed killer since you planted your boxwoods? Most of these products contain glyphosate as the active ingredient; it will kill all green growth that it comes into contact with. Although it was not intentionally sprayed on the boxwoods, a wind gust could easily carry this liquid spray and have killed that part of your plants.
Typically when evergreens die back they do not put on new growth to replace the lost. Boxwoods are tough, and it is helpful that these are settled and otherwise healthy plants. A light dose of fertilizer may help, but do not overdo it because too much food can have the reverse affect. If they do not put on any new growth in the next month or so, you might consider replacing them.
Q When is the best time to prune back my butterfly bush? I would like to concentrate the growth a bit lower, as the upper branches were on my roof (it is planted outside a one-story part of the house). I understand about directional pruning, I just didn’t know when, as new growth is now sprouting. —Anne Jones, Richwood
A Butterfly bush (Buddleia davidii) is a wonderful addition to any sun-loving garden, especially if your goal is to attract wildlife. Hence the name, these plants are certain to attract butterflies and even hummingbirds.
The best time to prune these flowering shrubs is late winter or early spring while they are resting and before they put on new growth. Since yours is already putting on new growth, be careful as you prune not to damage the tender new growth.
As a general rule we prune spring-flowering shrubs after they have finished blooming. This includes all plants that flower before June 1. For the summer-flowering shrubs, those that bloom after June 1, they should be pruned during the winter months or in the early spring before new growth begins. Pruning our plants rejuvenates them, encouraging new growth and larger flowers.
Butterfly bush blooms on new wood (current season’s growth) so they can be pruned back hard. Ideally, you want to cut it back to around 12 inches annually. This seems drastic but Buddleia are tough plants that respond well to hard pruning. They are woody near the base of the plant but produce new herbaceous growth year after year.
When you prune, make certain that your tools are clean and sharp. Feel free to thin out the plant to improve air circulation. This summer as your plant blooms and the flowers fade it is a good idea to remove the spent flowers. This will promote continuous blooms throughout the season and into the fall.
Q I want to grow herbs outdoors in 4 or 5 cinder blocks on the ground (on top of dirt but added dirt in the holes of the blocks), and though it’s April, it is still cold at night, almost freezing some nights. When would be a good time to put the seeds in the dirt? —Jozsef Zseger, Radcliff
A It is that time of year again, and in the next month we will be safe to plant summer annuals. Some herbs are perennials for us and will come back from year to year. Others are considered annuals. When grown in containers they are more exposed to the elements, but many will survive the winter and thrive the following growing season.
To grow a successful herb garden, there are a few factors to consider. First, making sure that they will be given sufficient sunlight is essential. Place your creative containers in the sunniest space of your garden. Next, fill your containers with high-quality potting soil. If it does not come with nutrients, you can add compost to the mixture. Drainage is also a consideration, but the cinder blocks allow for excellent drainage. You might want to break up the soil surface where they will be placed before planting them.
Depending on the herbs that you choose, you can purchase plants or seed packets. Each seed packet will have specifics in terms of germination, and you can start them indoors if you want to get a jump-start. Have fun choosing your herbs, and don’t forget you can dry them or add olive oil to the foliage and store them in ice cube trays. This way you can enjoy them all year long.
Q My weeping cherry tree is blooming, but has some dead limbs. Also, some bark is split. Some white stuff is on those spots. This tree is a gift from my retirement. I don’t want to lose it. It’s 3 years old. What can I do to save it? —Margaret Webster, Versailles
A Weeping cherry trees are lovely this time of the year, but these ornamentals are not free of insect and disease issues. From the picture that you sent, it looks like your retirement gift is not so happy. White fungal growth typically appears as a secondary issue and is a good indication that the tree is not healthy.
Have you noticed any wet looking areas or oozing on the trunk or branches? Splitting bark is also a bad sign and the dead branches are a result of this. When the inner layers of a tree are exposed it makes it easier for additional insects and disease to enter, causing further decline in the health of the tree.
Hiring a certified arborist is the best bet for your tree. He or she will be able to properly prune and treat with a fungicide. Your county Extension Office may have recommendations for certified arborists in your area or a local garden center/nursery may have one on staff. I’m sorry I don’t have more encouraging advice.
Q Our back yard has fruit trees and used to have beautiful grass. It borders the woods, and moss has covered about 80 percent of the yard and smothered out the grass. What would have to be done to get rid of that much moss and get my grass back? Your help would be greatly appreciated. —Fred E. Brewer, Brodhead
A I hope your fruit trees are productive for you! I suspect that as the fruit trees matured, they have shaded out the grass and the moss has moved in. Moss thrives in shaded, moist, and acidic environments. Soil compaction and improper mowing can also contribute to the spread of moss. Given the right conditions it can spread rapidly.
In your case, I assume it was living in the bordering woods and has moved its way into your lawn. Your lawn was probably originally seeded with a sun-loving grass blend that is no longer suitable. If turf grass is to be grown, you will need a shade-loving blend.
Before raking up the moss and seeding, you will want to have your soil tested. Your local Cooperative Extension Office is the best source for having this done. You can reach the Jackson County offices at (606) 287-7693. You may also consider incorporating some shade-loving plants if the space allows.
It’s not realistic to completely eradicate the moss, but with the results of your soil test and recommendations taken, as well as choosing the proper grass seed, you can once again have a lawn and not a moss garden.
March 2016 Issue
Q We’ve recently built a new home, and our entire front “lawn” is sloped at approximately 15-20 degrees, and measures approximately 50 ft. by 200 ft. It receives plenty of sunlight, was sodded with fescue in June, and is healthy. But the slope is creating a major problem for mowing. I am seriously considering converting from my manicured lawn to a maintenance-free stand of native Kentucky grasses, or some kind of low groundcover. Because of the area, it seems that any selections should be quick “spreaders.” Or is my entire idea even feasible? —John Cummins, Alvaton
A Planting on a slope has its challenges, but so does mowing one! Switching out fescue for ornamental grasses is certainly an option, but with the space you are dealing with you might consider combining plants with spreading/clumping growth habits. This will add texture, layers, and color throughout the year.
A landscaping plan that incorporates different plants can create a no-mow front yard. Of course, there is always maintenance, but not with a mower. It is a great opportunity to create a beautiful front garden to showcase your new home. You can always have a plan drawn for you by a local landscape designer. They can also help in terms of labor and maintenance if needed.
The Extension Service in Warren County is a great place for resources. The horticulture agent will be able to help you get your soil tested and hopefully give suggestions for local designers. The following link is a publication provided by our Cooperative Extension Service that discusses planting on a slope and also has a list of recommended plants for sloped sites. http://www2.ca.uky.edu/agc/pubs/ho/ho78/ho78.htm
Q Our house is next to a convenience store and car wash. Their refrigeration units are next to our property line, so we get a lot of water down that side. Cucumbers and tomatoes I planted next to our fence drowned and died. Is there some kind of tall greenery I can plant for privacy that will take a lot of water? Thanks for any help.—Sonnie Shelton, Manchester
A It sounds like you have a challenging space to landscape. A fairly consistent overhead/underground mist with potential harmful chemicals is a lot to ask of anything living to tolerate.
Anytime plants are exposed to an environment that is less than pleasing or even harmful, they will decline in health and eventually die. Foliar issues are more common when plants are watered incorrectly. It is important to water only the soil surrounding the base of the plant so the roots can take it up and send to the rest of the plant; otherwise, water remaining on the foliage can lead to mildew and other fungal issues.
In your case, it’s out of your control, so rethinking your garden space is the next step. The quality of the ground water should also be taken into consideration when planting edibles. Hopefully you have another area with good sunlight where you can have a vegetable garden. A raised vegetable garden may also be an option so that you can control the moisture levels. For a list of ornamentals that are tolerant of excessive moisture, you can visit: http://www2.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-OR-W-4.pdf. This publication is a reliable source from our Extension service in collaboration with land grant universities.
When choosing any plant, make sure to take into consideration available sunlight, mature size, and any restrictions in terms of surroundings. You can have your soil tested through the Extension service as well.
Q My daughter and son-in-law built me a big, high-off-the-ground wood box for planting herbs. I need to know what kind of dirt to fill sections with, and do I need rock on the bottom of the box? Also, do you have some kind of planting guide help? I am excited about getting it going this spring, so I need the right kind of help to get it planted. Thanks for any help to guide me on the way.—Joyce Beckett, Falmouth
A What a sweet gift your daughter and son-in-law made for you! Functional and something you can enjoy for years to come. Growing herbs in containers is so much fun and incorporating them into your recipes benefits everyone.
You will want to fill your raised bed with quality potting soil and compost for nutrients. Do not use topsoil as it will not allow for proper drainage. Are there drainage holes or slats between the wood for drainage? If so, no rocks are necessary.
Be sure to place the planter in an area where it will receive 6-8 hours of direct sunlight each day. To determine how much soil/amendments you’ll need, measure the length x width x height of the planter in feet. Most bags are sold in cubic feet so this will help estimate how many bags you’ll need. For example, a 4×4 foot planter will need approximately 4-5 bags. Hen manure and worm castings are great choices for nutrients, but be sure you add more potting soil than amendments. A rough estimate to follow is one bag of amendments per 2-3 bags of potting soil.
After the planter is filled, the fun can begin! Choose herbs that you like to cook with, and then decide if you want to start them from seed or buy actual plants. Take into account the growth habit of each herb and incorporate upright, spreading, and trailing herbs. Plant the taller ones in the middle and the trailers on the edge. Basil, thyme, rosemary, cilantro, sage, lavender, and parsley are the most common herbs, but for a detailed list of herbs we can grow in Kentucky visit https://www.uky.edu/Ag/CCD/introsheets/herbs.pdf. This publication is available from our Cooperative Extension Service.
The only herb I would recommend avoiding is mint. Plant this in its own container, or it will take over. Some herbs are considered hardy perennials so keep this in mind when choosing the herbs you want to incorporate.
I love being able to go into the garden and choose herbs for the next meal, and I hope you will, too!
Q I started out with six regular hellebores. They have multiplied nicely. They are in shade under the large canopy of a tree. The soil may have been enriched all these years by leaf drop before we moved here. However, I found there was quite a bit of gravel mixed in. I removed what I could, but drainage is probably great. After discovering Yew Dell and other great nurseries, I purchased some hellebore hybrids—Peppermint Ice, Pink Frost, etc. The regular ones look fine but the hybrids are not thriving. They seem to have gotten smaller and they aren’t blooming as well either. Do they need more light? Better soil? I have another shady area they might like better, but do they dislike being moved? I’m afraid if I don’t move them, they’ll die out anyway. They also get winds from west/northwest.—Heather Evans, Glens Fork
A I love that you are growing hellebores. They seem to get overlooked in the garden centers and nurseries, but a nice grouping of them provides four seasons of interest and produces lovely blooms in the late winter when we gardeners are missing them most.
Hellebores are not fans of being transplanted, but if they are not thriving where they are, then this might be an option. First, I would consider how long they have been living there. If they are relatively new additions to the garden, I would give them time to establish their roots; some hybrids are slow to become established. If they have been growing in this same location for several years, it may be that they are not receiving adequate nutrients, sunlight and/or moisture.
Morning sun is ideal with moist but well-drained, nutrient-rich soil. These evergreen perennials will benefit from a side dressing of compost each spring. Even established plants will need additional water during hot, dry summers. Early spring would be the time to move them if all other requirements have been met.
As with all transplants, it is best to have their new homes dug before lifting the roots from the soil. Keep as many roots attached as possible and replant them immediately. Water well and treat like any new planting, in terms of care. As for the wind exposure, evergreens are more susceptible to winter burn if they go into winter without sufficient moisture. If your plants have brown/black foliage, go ahead and cut them back to the stem.
Q I recently received a beautiful orchid from a friend. It was full of beautiful shades of blue. I enjoyed it so much. When the blooms fell off, I saved them and placed them around the base of the plant and continued to enjoy their brilliant colors. I have been placing a couple of ice cubes weekly on the base of the plant, as I understand they do not like much moisture.
It has been almost 9 months now and still no bloom has appeared anywhere I can see. What do I need to do differently? Will the blooms come out at the end of the stems where they were before? Any tips you can give me would be most helpful. Does it need any sort of plant food? Other friends and family that have orchids tell me to be patient that theirs have bloomed and mine will, too.—Glenda Adams, Somerset
A I agree with your friends and family, and it’s worth waiting for. The flowers that orchids produce are both lovely and long-lived. The thought of caring for orchids can be intimidating, but these delicate looking plants actually just need a few requirements to thrive. There are many species of orchids and some are pickier than others, but the Phalaenopsis species is the most common one we see sold as houseplants.
Understanding how they live in their native environment is helpful in caring for them indoors. Orchids are considered epiphytes—they attach themselves to tree trunks and live off of the nutrients provided by plant litter that falls from the tree canopy. They survive on moisture that Mother Nature provides. The roots are not buried in soil so it is essential that we use a bark-based potting medium made specifically for orchids. Watering once a week is fine. Adding a water-soluble orchid fertilizer once a month is recommended for optimal blooms. Using a half-strength dose of food is fine. It is always better to under-water and feed than to over-water or to over-feed your orchid.
As for the stem that is still on the plant, go ahead and cut it back to about an inch. It is not common for orchids to produce flowers on the same stem and if they do the flowers are smaller. Removing the stem will allow your orchid to concentrate all of its energy on the roots, foliage, and producing a new stem that will eventually bloom again. It is a process that usually takes 3 to 4 months. If the plant is healthy and happy it can bloom up to a couple of times each year, with the blooms lasting for several weeks. For now, keep your orchid in a space where it will receive bright filtered light. A south-facing window is ideal.
February 2016 Issue
Q I’d like to grow edible plants in my garden but want to make sure we don’t have a lead contamination problem. Could you please tell me where to get the soil testing done? I know lead tends to accumulate more in leafy greens, and less in fruits like tomatoes, peppers, etc. How about seeds?—Cath M., Danville
A It is a good idea to have your soil tested if you are concerned about high levels of lead in your soil. For general soil testing in Kentucky, I always suggest contacting your County Cooperative Extension Service, but the University of Kentucky lab does not test for lead. The Boyle County office suggests an independent lab in Owensboro. Waters Agricultural Laboratories in Owensboro charges $15 and will give you the results within a week.
To take a sample, dig up 1-1.5 cups of soil in your vegetable garden. Take small samples randomly throughout the garden and then combine all of it into a plastic zipped bag. To avoid inaccurate results, use a plastic, chrome, or stainless steel spoon or digging tool to collect the soil.
Send it to Waters Agricultural Laboratories at 2101 Calhoun Rd., Owensboro, KY 42301. If you want to contact them their phone number is (270) 685-4039. You can send a check along with the sample or they will invoice you later. Include your contact information with your sample. It is always best to purchase seeds from a reliable source. If you are looking for organic seed options, Baker Creek and Renee’s Garden are both good mail order options.
Q We have several fruit trees, which we planted 5 years ago in our back yard of 1 acre. We have two cherry trees, two apple trees, one peach tree, and one plum tree. They all produced fruit, but as soon as the fruit started growing bigger, the fruit started drying up, so all we had was a bunch of brown, dried fruit, and that was on all the trees. I tried to find out what was causing this, but couldn’t. Could you please tell me what is causing this and give me a cure before they start blooming again?—Charles Worland, Munfordville
A There is nothing better than being able to harvest fruit from your own garden. It can be just as disappointing when things don’t work out as planned. Other than the rotted fruit, did you notice any unusual growths or sunken parts on the foliage, trunks or braches?
Cherries, peaches, and plums are all considered stone fruit, which are susceptible to a fungal disease called brown rot. Although there are other diseases, brown rot is the most common that we deal with in Kentucky. It’s more common during warm, humid weather and especially during extreme wet periods. Apples can also be susceptible to disease problems, including rot and blight.
For a positive diagnosis you can have a certified arborist come out, or take a sample to your agriculture/horticulture agent at your County Cooperative Extension Service. The Hart County offices are located at 505 A.A. Whitman Lane or you can reach them at (270) 524-2451.
It is always best to choose disease-resistant cultivars and provide them with ideal growing conditions. Good sanitation is essential in eliminating future infection. All infected fruit and plant debris should be removed and disposed of. Otherwise, spores will over-winter on mummified fruit and recontamination will occur the following spring as the spores are dispersed by wind and rain. In some cases, a spray program is necessary. The following link is a publication on homegrown fruit in Kentucky: www2.ca.uky.edu/agc/pubs/id/id21/id21.pdf
Q I have two hibiscus trees I brought in for the winter. They are in my foyer where they get light from the window above. One is fine, but the other has a dirt-like or sand-like sticky substance on the leaves and flowers, both on top and underneath. What do I do, if anything? Also, how often should I water?—Michelle Lee, Prospect
A This is the time of year when in some cases the plants we brought inside to over-winter start letting us know that they are not happy. Any time we move plants from one environment to another it causes stress on them. We simply can’t provide adequate sunlight, temperature, or humidity indoors. Too much moisture can also cause plant stress, and when plants are stressed, they are more susceptible to insect and disease issues.
Tropical hibiscus are no exception, and from what you have described it sounds like aphids have been feeding on your plant. Aphids are little insects that have piercing/sucking mouth parts. As they feed on the plant they also secrete a sticky substance known as honeydew. This will drip on the rest of the plant and on the floor around your plant. Black sooty mold can also develop on the honeydew.
Depending on how heavy the infestation is, you can sometimes just wipe them off, but usually a combination of a granular systemic and foliar spray is your best bet. Aphids are very efficient at reproducing, so it is best to treat your plant as soon as you notice them. Make sure to purchase products that are labeled for aphids and safe for hibiscus.
As for watering, less is better during the winter months. Do not let the soil completely dry out, but it should never be sopping wet either. Your watering routine will depend on the temperature and humidity of your home, but every 7-12 days should be sufficient. Always check the soil for moisture before adding any more. If the soil is dry to the touch a couple of inches down, then go ahead and water, but otherwise it is not necessary. When you take them back outside in the spring, move them to a shady spot and slowly acclimate them to the full sun.
January 2016 Issue
Q I have a perennial bed that I want to kill out and plant a small garden this spring. It is very thick with vegetation right now. I’m concerned about spraying it then sowing vegetables. I sprayed it a couple of times in the fall, which helped very little. —Stacy May, Lexington
A Switching out a perennial bed for a vegetable garden is certainly doable, but the task of getting the perennials out of the way is the first order of business. The lack of success with spraying may have to do with what you sprayed, how much you sprayed, what you are trying to kill, and if the plant was actively growing or able to absorb the active ingredient (likely glyphosate).
Since your goal is to replace a perennial bed with a vegetable garden, you are better off digging up the plants, reworking the soil, and replanting. If this is an established perennial bed, you will have the roots to contend with even if you just kill the plants, so you might as well just dig up the healthy plants and their roots so you have a clean bed to plant your veggies in.
Digging out the existing perennials is the most environmentally friendly option and really makes the most sense in terms of replanting. Glyphosate and other chemical sprays have their place, but knowing you are going to eat the plants growing in this soil is just another good reason to hand-dig.
Q When should I cut back or shape my boxwoods for the year?—Ronald Reeser, Burlington
A Boxwoods (Buxus) can serve several purposes in a landscape. Whether they are used as a specimen, hedge, or topiary they provide year-round interest. These evergreens are considered low-maintenance and can thrive in a variety of environments.
The best time to prune is late winter or very early spring just before new growth begins. Pruning now would make them more susceptible to winter injury. The one exception to this rule is if you notice dead or diseased branches. If this is the case, go ahead and prune those parts out now.
Whenever you prune be sure to use clean, sharp pruners and don’t remove more than one-third of the plant during a single pruning session. If you want to reduce the size drastically, it is best to do so over a couple of years. For now, if you haven’t already mulched, apply a few inches around the base of each plant to help protect them during the winter months.
Q What tree would you not find in Kentucky?—Lonnie Lockard, Artemus
A There are many trees that you will not find in our Kentucky landscape. All plants, including trees, have their own evolutionary history. Although some have been introduced to different parts of the world and thrive, others are only happy growing in their native environment.
When considering a new planting, it is always best to purchase a species/cultivar that is disease-resistant and recommended for your hardiness zone. We also have to take into account soil condition, space limitations, and available sunlight.
If you have not had your soil tested recently, this can be done through your county Cooperative Extension Service. It’s always good to know if your soil needs improvement before planting. Lucky for us, Kentucky’s forests are among some of the most diverse in the world! We have a lot of trees to choose from.
For a list of native trees visit: http://www.uky.edu/hort/Native-Trees-of-Kentucky. Trees can be planted year-round as long as the ground is not frozen, although you will typically find a larger selection at your local garden centers/nurseries in the spring.
December 2015 Issue
Q We have two boxwoods in plastic pots on our covered porch. The temperatures are dropping in the teens: what should we do to protect them?—Michelle, New Haven
A Planting evergreens in containers is a great way to add winter interest to any space. There is always a risk when doing this, especially if you live where winter temperatures dip below freezing for any extended amount of time. Different species of boxwoods vary in terms of hardiness, but most are considered hardy to zone 6 and will survive temperatures as low as -10 degrees F.
The main concern with evergreens in containers is that they dry out faster and do not have the warmth of the surrounding soil like those planted in the ground. The goal is for them not to go into dormancy without sufficient moisture, as this makes them more susceptible to winter burn. As the soil thaws, make sure to hand water if they are not in a position to receive rain or snow and check that the containers have drainage holes.
Add a few inches of mulch to the top of the soil for insulation. While it may not look very nice, surrounding the containers with straw bales or wrapping with blankets will also help insulate them. This helps to prevent excessive freezing and thawing cycles, which can damage roots and potentially kill the plants. The good news is that plants do not feel wind chill so temperatures in the teens should not damage your boxwoods.
November 2015 Issue
Q I realize that this season has not been a good one for tomatoes, but I have a disease problem. Last year, I noticed the foliage on the tomatoes becoming spotted and finally drying up along with some stems. The plants still produced some fruit. I moved the planting to another area this year and had the same result. As I am in the raised bed situation, can the soil be treated with anything or will adding new soil on top help? —Sally Porter, Gracey
A The extreme fluctuations of wet and dry conditions combined with cooler than average temperatures did not provide any of us with a bumper crop of tomatoes this season. Less than ideal growing conditions can cause plant stress and encourage insect/disease issues. This is why crop rotation is so important. It really would be best to get a positive identification as to what you are dealing with. You can take a sample to your county cooperative Extension service.
The horticulture or agriculture agent(s) can give you specifics in terms of your tomatoes and prevention options. Tomatoes require a minimum of 8 hours of sunlight each day. They grow best in nutrient-rich, well-drained soil and compost. Planting disease-resistant cultivars is essential to a healthy crop.
Q My Lilac is not doing well. I planted it 7 years ago, and it started quite healthy and finally bloomed beautifully in 5 years. But since then, it stopped growing and had spider webs on the branches. It does not look healthy. After it bloomed in 5 years, it has only bloomed once and only bloomed partly. I noticed some of the branches were dead, so I cut them off. I don’t know what to do to make it healthy or how to. —Hiroko Schecter, Bowling Green
A All plants are happiest when they are given optimal growing conditions. Each plant has its own specific requirements, and Lilacs (Syringa) prefer to grow in fertile, well-drained soil with at least six hours of sunlight each day. Good air circulation is important for Lilacs. Depending on the species/cultivar that you are growing, some are more disease resistant than others. Lilacs can be susceptible to several different insect and disease issues especially if they are not happy with their growing conditions.
You can take a sample to your Cooperative Extension Service or to a reputable garden center for a proper diagnosis. The lack of blooms can be due to insufficient nutrients and/or sunlight, but flower buds can also be damaged by spring frosts.
If necessary, Lilacs should be pruned shortly after they have finished blooming or anytime you notice a dead, diseased, or crossing branch. Older Lilacs may also benefit form having one-third of their oldest branches pruned back to the ground. This will help rejuvenate the plant and encourage new growth. For now, clean up all debris around the plant and add 2-3 inches of mulch around the base of the plant to help protect during the winter months.
Q I am working with a community garden and Ironweed is a major problem. Is there an organic product that will eliminate this problem? —Beverly Kegley, Mt. Sterling
A First, I have to commend you on being part of a community garden. These spaces are beneficial on so many different levels, and although the idea of community gardening is not new, it has certainly has made a come back in recent years. Like any garden, it can be rewarding and challenging at the same time. Ironweed (Vernonia) is a large group of tough plants. Some cultivars have been selected for home gardens and are especially popular in butterfly gardens, but other species can be troublesome and difficult to eliminate.
Ironweed was given this name for a reason; even with gardening tools it is difficult to remove the taproots and thick rhizomes of this plant. Eradicating it completely will be an ongoing project, but getting it under control is the first step.
Remove all foliage as soon as you notice any new growth. This will starve the plant of essential nutrients and prevent it from flowering and producing seed that will turn into more plants. When you turn your soil and prep it for planting, this is a great time to remove any willing roots.
Corn gluten meal and other organic pre-emergent products will prevent the Ironweed seeds from germinating, but it will also stop wanted seeds from sprouting as well. Spot spraying with vinegar and/or pouring boiling water can also be helpful with the taproots, but make sure it does not come into contact with other plant material in the bed. Studies that have been conducted to eliminate Ironweed have found that mowing in combination with herbicides did not eliminate this herbaceous perennial completely. Not to discourage you, but just to let you know what you are up against. A lot of elbow grease and persistence will pay off in this case.
October 2015 Issue
Q What kind of shrubs would you put in front of your house to replace boxwood shrubs? —Agnes Smith, Taylorsville
A There are many alternatives to boxwoods, but before choosing a replacement, it is good to know the site conditions—especially if the boxwoods were not happy. How many hours of sunlight does that space receive? And what are the soil conditions? Each plant has specific requirements in terms of growing environments, and finding the right plant for your space is key to a healthy, long-lived garden.
If you have not had your soil tested recently, you can contact your county Cooperative Extension office for instructions. Assuming that you want evergreens and they will be growing in part sun, there are some azaleas that would provide winter interest.
Aucuba japonica and pieris japonica are also good options. Nandina, inkberry (Ilex glabra), yew (Taxus baccata), Japanese plum yew (cephalotaxus), and cherry laurel (Prunus laurocerasus) could all work as well.
Q The north side of my home was buried in snow for three plus weeks and it killed a long-standing full growth of English Ivy! It gets little to no sun (some late afternoon sun in summer) and much less as the fall arrives. My soil is moist most of the time. I need something like in the back of my home, which has spruce evergreens that are maybe 15 years old and fully grown to 8 feet tall by 5 feet wide, but I don’t think they would grow in that much shade. What can you suggest? —Michael Howell, Russellville
A I have to say that it’s not easy to kill English Ivy (Hedera helix)! Once established, it can be a battle to eliminate. Have you noticed any new growth? I mention this because I am wondering how moist your soil is? Does it drain well when we get a lot of rain? If not, you may want to amend the soil before planting anything new.
You can have your soil tested through your county Cooperative Extension Service. The Logan County offices are located at 255 John Paul Road and the phone is (270) 726-6323. As for larger evergreens that will grow in deep shade, this can be tricky. Unfortunately with these growing conditions, there are fewer options than in a sunny location.
Aucuba japonica, Mahonia, English Laurel (‘Otto Luyken and ‘Schipkaensis’), Pieris and some Azaleas are all evergreen options. Boxwoods and Taxus are also options.
These plants can adapt to heavy shade, but the ones that flower will not likely do so given the light levels. You mentioned that the Ivy was near the house so make sure to take mature size into consideration before purchasing new plants. Now is a great time to plant shrubs, so check with your local garden center to see what catches your eye.
Q I need to trim down my Rose of Sharon. I never expected it to be so wide and tall in seven years! I would like to know when is the best time to trim down and how low or how high from the ground should it be trimmed down? —Hiroko Schecter, Bowling Green
A Rose of Sharon (Hibiscus syriacus) are summer/fall blooming shrubs. As a general rule, we prune summer flowering shrubs during the late winter/early spring, but if your Rose of Sharon has any dead, diseased or crossing branches go ahead and prune now.
Otherwise, for shaping purposes and to reduce size, it is best to prune while they are dormant. Remove no more than one-third of the size of the plant each year. If you want it smaller continue to remove one-third each year until you’re happy with the size and then maintain yearly.
Rose of Sharon are large deciduous shrubs that will reach 8-10 feet tall and 4-6 feet wide. It sounds like yours is very happy where it’s growing. When you prune be sure to use rust-free, sharp pruners and remember that these are late to leaf out in the spring. Enjoy the blooms!
Q Do I need to cut back our butterfly bushes, and if so, in the early spring or late fall, or winter? —Peggy Lucas, Burgin
A As gardeners, we prune to thin, shape, and rejuvenate our flowering shrubs. The correct time to prune them depends on what the shrub is and what time the year it blooms. As a general rule, we prune spring-flowering shrubs after they have finished blooming. This includes all plants that flower before June 1.
For the summer-flowering shrubs, those that bloom after June 1, they should be pruned during the winter months or in the early spring before new growth begins. Butterfly Bush (Buddleia) are considered summer-flowering shrubs so, the best time to prune them is late winter/early spring before new growth begins. Pruning now may encourage new growth that can be damaged by any early frosts. Pruning while they are dormant will make them less susceptible to winter injury and other potential problems.
If your reason for pruning is to remove dead/diseased or crossing branches, go ahead and get your pruners out. Otherwise, waiting until later in the winter or early spring before they break dormancy would be in the best interest of your butterfly bush.
It is best not to remove more than one-third of the size of the shrub at one time. Do this year after year to maintain the size you want. Use a clean, sharp, and rust-free pair of pruners. Make your cuts flush to the nearest intersecting branch so there are no stubs. If you need proper pruning instructions visit http://www.ca.uky.edu/agc/pubs/ho/ho59/ho59.htm.
September 2015 Issue
Q I have little holes in all my hostas. Can you tell me what type of bug does this and what’s the remedy? —Debbie Wesslund, Louisville
A When it comes to hostas, the most common pest problem is the slug. These two seem to go hand in hand and the damage of small, round holes is exactly what you have described. Slugs are nocturnal feeders, so you will not find them on your perennials during the day. Control options include diatomaceous earth and Sluggo, which are both organic products you should be able to find at your local garden center. As with any product, be certain to follow recommended application rates.
Home remedies include a shallow bowl of beer. Leave the bowl of beer out at night while the slugs are feeding and in the morning you will find the culprits and be able to dispose of them. Melons are also great and any kind will work. Place the hollowed-out part facedown in the garden. Again, do this at night and the next morning you will have a melon full of slugs. If you start a control program early next spring, you should be able to deter these slimy pests.
Q I have beautiful cucumber vines that are loaded with bloom, but no cucumbers. I also very pretty bean vines with no bloom. What advice do you have to help them bloom? —Bob Fulks, Beattyville
A The answer may be as simple as age. How old are your vegetables? If you started them from seed and got off to a late start, it may be that the cucumber has formed the male flowers and not the female yet and the beans just haven’t started flowering at all.
In the case of the cucumbers, it could also be a pollination issue. Have you noticed any bees on the flowers? If the cucumber has male and female flowers that are not being pollinated, you would not get any fruit. Male and female flowers can be differentiated by the lack of fruit on the male flower. If this is the case, you can pollinate by transferring pollen from the male flower to the female flower using a small paintbrush.
So back to your beans…if they are old enough to flower and are growing in full sun (at least 6 hours), it is likely a nutrient issue. Have you fertilized your beans? If so, and they were given too much nitrogen, this will cause lush vegetative growth, but prevent blooms from forming. On the other extreme, if you have not added compost or other nutrients this season, the beans may need some to flower. You can have your soil tested through your county cooperative Extension service.
Q I would like an edible, mixed hedge along the fence separating me from my neighbors. What kind of plants would you recommend? Would rosa rugosa, gooseberry, currant, or huckleberry send out runners into my neighbors’ yards? Would they look good together in a row? I’d like to mix several types of plants that have similar shape/height/width so the hedge would look good. Any advice is appreciated. —Lin T., Danville
A I love the idea of incorporating edibles into the landscape. There are a few factors to consider before choosing plants. First, how much space are you dealing with and how many hours of sun does it receive throughout the day? Secondly, what is the soil like? Does it drain well? Or could it benefit from amendments?
If you have not had your soil tested recently you can have this done at your county cooperative Extension service. Visit the Boyle County Web site at: https://boyle.ca.uky.edu.
Each plant is going to have its own requirements in terms of soil, and each will have its own mature size and growth habit. For the sake of it not being hodgepodge, it’s best to group like plants together. If you have enough space, you could choose a couple of different berries and under plant them with strawberries. Blueberries would be a great choice because of their shrub-like growth habit and intense fall color. Gooseberries and currants are a bit less tamed in appearance, but will serve the purpose of a hedge. Whatever you choose to plant, be sure to choose disease-resistant varieties. For detailed information on growing fruit in Kentucky visit: http://www2.ca.uky.edu/ANR/PDF/Growing%20Fruit%20at%20Home%20in%20Kentucky.PDF and http://www.uky.edu/Ag/NewCrops/introsheets/currants.pdf.
Q I realize that this season has not been a good one for tomatoes, but I have a disease problem. I have three raised beds, so my planting area is limited. Last year, I noticed the foliage on the tomatoes becoming spotted and finally drying up along with some stems. The plants still produced some fruit. I moved the planting to another area this year and had the same result. As I am in the raised bed situation, can the soil be treated with anything or will adding new soil on top help? —Sally Porter, Gracey
A It certainly has been a challenging year for growing tomatoes. The extreme fluctuations of wet and dry conditions combined with cooler than average temperatures did not provide any of us with a bumper crop of tomatoes this season. As with any plant, each is more susceptible to insect and/or disease issues if they are stressed. Less than ideal growing conditions can cause plant stress and encourage insect/disease issues; once introduced, they can ruin your crop for several years.
This is why crop rotation is so important. Anything that is going to over-winter in the soil will not be remedied by adding a new layer next growing season. It really would be best to get a positive identification as to what you are dealing with. It may be verticillium wilt, but just to be sure you can take a sample to your county cooperative Extension service. The horticulture or agriculture agent(s) can give you specifics in terms of your tomatoes and prevention options. Each problem is treated differently so it is best to know exactly what is going on in your garden.
Since we can’t control the weather, we have to do everything possible to create optimal growing conditions for each plant. Tomatoes require a minimum of 8 hours of sunlight each day. They grow best in nutrient-rich, well-drained soil. Hopefully your raised beds are in a nice, sunny location and they were filled with quality soil and compost. Planting disease-resistant cultivars is essential to a healthy crop.
Visit: http://www2.ca.uky.edu/agc/pubs/id/id133/id133.pdf for a list of disease-resistant cultivars for Kentucky gardeners. For now, keep the area around the tomato plants free of plant litter.
August 2015 Issue
Q I planted a trumpet vine seven years ago and it still hasn’t bloomed. It’s facing west and gets plenty of afternoon sun, and grows quite vigorously. How can I get this thing to produce flowers? —Sandra Hash, Buffalo, Kentucky
A Trumpet vine, Campsis radicans, is a fast-growing deciduous vine that can take several years to flower. This perennial vine produces flowers on new growth but it can actually take up to 10 years before you see your first blooms. There are a few reasons why older vines do not bloom, but we can rule out age and lack of sufficient sunlight in your case. Too much nitrogen fertilizer could be another possibility.
Trumpet vine does not need to be fertilized; it thrives in poor quality soil and will take up everything it needs from the existing soil. If you do fertilize, use half-strength recommendations. Do you prune your vine? If so, and you are cutting it back in the late spring, you may be removing potential flowers; the best time to prune is late winter or early spring before new growth begins.
That said, pruning can actually encourage flower production, so when early winter/spring arrives you can cut back some of the older, woodier growth to prompt blooms for next season.
Q I have Crape Myrtle that is 15 feet tall. When and how do I trim it, and how much? —Tom Coomes, Hardinsburg
A This past winter was a hard one for a lot of Crape Myrtles (Lagerstroemia indica) in our area. I have seen quite a few die back to the ground, but have since recovered nicely. There are many cultivars and hybrids of Crape Myrtle, and some are hardier than others. They are available in a wide range of flower color as well as mature size. The best time to prune them in Kentucky is during the spring. Waiting until the fall can make them more susceptible to winter damage.
That being said, if there is dead wood, go ahead and get your pruners out. It is best to remove and dispose of any part of the tree that is no longer thriving. Leaving dead wood on the tree will give it an untidy appearance and can encourage insects/disease. Be sure to make your cuts as close to the healthy intersecting branch as possible without harming any healthy wood. Sharpen your pruning tool and clean afterward just to make sure you are not spreading potential disease.
Crape Myrtles bloom on new growth so as long as yours has put on new growth this season, you will enjoy flowers before you know it.
Q I’ve tried to grow figs—three years, three different trees. I’ve had soil tests done, changed locations, etc. The locally purchased plants were supposed to overwinter. They produced a dozen or so fruit, but they did not overwinter. Any advice? —Clifton Keller, Lebanon Junction
A Growing figs in Kentucky is possible, but to have them survive the winter, it is essential that we plant hardy varieties. Do you know which ones you have grown? Brown Turkey, Chicago hardy and Celeste are good choices for Kentucky gardeners. They are best planted in a nutrient-rich, well-drained soil given south/west exposure. Figs require full sun (a minimum of 6 hours of direct sunlight).
I have had a Chicago hardy for 5 years; it dies back to the ground every winter and is late to leaf out, but does eventually flourish and fruit. I do give it added protection even though there are structures nearby. A thick layer of mulch or straw will help protect the roots during the coldest part of the year.
For more detailed information on growing figs in Kentucky, click here. This is a link from our Cooperative Extension Service. I hope this is helpful and your fig survives this upcoming winter.
Q My wife and I are first-year tomato gardeners. We decided to try growing tomatoes in 5-gallon containers. We have a total of 17 containers. About four of them are cherry-type tomatoes, but the rest are indeterminate varieties ranging from German Johnson to Pink Brandywine. My question, my problem: We are dealing with blossom end rot on all of the indeterminate tomatoes. I have used Cal/Mag and End Rot, bat guano, and tomato tone. I bought a cheap device to measure moisture and fertilizer, as well as pH, but we still are dealing with blossom end rot. Any advice on how we can combat this? —Stan Bickel, California, Kentucky
A It sounds like you and your wife have taken every measure to grow an abundance of organic tomatoes. Seventeen tomato plants for the first try is very impressive. Unfortunately, gardening can be frustrating especially when things don’t work out like we intended.
Blossom end rot is a common physiological disorder caused by inadequate growing conditions. A combination of uneven moisture levels and too much nitrogen makes tomatoes more prone to this disorder. Blossom end rot is caused by a calcium deficiency; either there is not enough calcium in the soil or the pH is off and binds the calcium so it’s not available to the fruit. We’ve had a lot of rain this season and fluctuations in soil moisture can be a problem especially if the soil does not drain well.
Growing tomatoes in containers is a great way to save on space, but if the containers do not have proper drainage the tomatoes will never be happy or productive. I assume your containers have plenty of drainage holes and are placed in a full sun location (a minimum of 6 hours). What is your watering routine? You always want to make sure that the soil is not moist before adding additional moisture. Avoid watering the foliage, and it is best to water in the morning. A thin 2-inch layer of mulch will help keep moisture levels consistent (even in containers).
Fertilizing with high amounts of nitrogen especially at rates higher than recommended can make our tomato plants more susceptible to this disorder as well. The recommended soil pH for growing tomatoes is between 6.5-6.7. The good news is that we still have plenty of growing season left and healthy tomatoes are hopefully in your near future.
For now, avoid adding fertilizer, keep soil on the dry side and discard all infected fruit. You have used top of the line soil and products to prevent blossom end rot, but sometimes less is better. I hope this is helpful and you have healthy, homegrown tomatoes very soon.
Q We planted what turned out to be a mixture of seeds in our garden. There is one particular plant that’s come up, which at the moment stands 3 to 4 feet tall with big green leaves and blooms that are forming with an orange/yellow flower (photo below).
Last week my husband had to dust all the plants with Seven Dust as they became inundated with flying bugs that began eating the large green leaves. He was concerned these bugs would get into the vegetable garden and start eating the plants. It seemed to work, but of course it rained causing a need to reapply. Can you identify the plant and recommend something besides Seven Dust to keep the bugs away? —Joyce Vanderwaal, Cox’s Creek
A The plant in question looks like it belongs to the Helianthus (sunflower) genus. The common sunflower (Helianthus annuus) has many cultivars. These ornamentals range in a wide variety of sizes and flower color. It sounds like yours will bloom a traditional yellow, but may not be one of the larger ones.
As far as insects on plant foliage, it is important to know what insect you are dealing with before treating them. Products are labeled for specific insects, and it would be a shame to use something that may not work. Have you noticed insects in your vegetable garden? Insects are host-specific so the ones in your flower garden may not be the same as in your vegetable garden.
Discouraging them is best done by planting resistant varieties and giving each plant optimal growing conditions. Good sanitation practices are also important. If you notice activity in your vegetable garden, there are many organic options including neem oil and insecticidal soaps. Most garden centers will have someone to identify insects, but you can always take samples to your county extension office, too.
Q What should I do with the foliage of my peony and bleeding heart plants once the blooms are gone? —Sharon Irvin, Columbia, Kentucky
A Spring bloomers are finished for the year, but if the foliage still looks healthy, it is best to leave them alone and allow them to absorb nutrients for next year’s blooms. In some cases, peony foliage can look bad especially if powdery mildew is an issue. If this is what you are dealing with, go ahead and cut back/discard the foliage.
Bleeding Heart (Dicentra) does not like the summer heat and typically dies back on its own, but we have not had extreme heat so far. The foliage adds interesting character to the shade garden, so enjoy it as long as it’s still attractive. Otherwise, you can remove it as well.
Q What kind of shrubs would you put in front of your house to replace boxwood shrubs? —Agnes Smith, Taylorsville
A There are many alternatives to boxwoods, but before choosing a replacement, it is good to know the site conditions—especially if the boxwoods were not happy.
How many hours of sunlight does that space receive? And what are the soil conditions? Each plant has specific requirements in terms of growing environments, and finding the right plant for your space is key to a healthy, long-lived garden.
If you have not had your soil tested recently, you can contact your county cooperative extension offices for instructions. Assuming that you want evergreens and they will be growing in part sun, there are some azaleas that would provide winter interest. Aucuba japonica and pieris japonica are also good options. Nandina, inkberry (Ilex glabra), yew (taxus baccata), Japanese plum yew (cephalotaxus), and cherry laurel (Prunus laurocerasus) could all work as well.
July 2015 Issue
Q I live in a restored downtown building. What’s the best way to do a rooftop garden?
A There are challenges in rooftop gardening, but the list of benefits goes on and on. Besides the aesthetics factor, simply adding plant material to your rooftop will help reduce energy needed for heating and cooling the building, improve air quality, and potentially reduce runoff. Larger plantings can also provide shade. The least expensive and most common option for a homeowner is creating a container garden.
Before adding any plant material to the roof, you should make certain that the roof is structurally sound and can handle the additional weight. The more involved option is to create layers, simulating a natural environment on top of the roof and walkways for maintenance purposes. The plant material would then be planted directly into the top layer of soil.
As for planting options, we have to take into consideration the increased exposure to sunlight, wind, rain, and whatever else Mother Nature whips up. Drought-tolerant plants, such as Delosperma Fire Wonder and Sedum Angelina, are good options, since these plantings will dry out faster than those in a traditional garden. Native plants are also good options as well as seasonal edibles.
Q I have several established flower gardens. What may I use to kill the weeds that will not harm my flowers? I have always pulled weeds, but am not as young as I once was and the weeds are beginning to take over. —Georgia Robertson, Russellville
A Weed control is an ongoing task for all gardeners. Even established beds require attention to prevent weeds from taking over. Of course, hand picking is an option, but if you are not up for it there are alternatives.
There are many weed-killing products available on the shelves of garden centers. These sprays are non-selective and will harm any desirable plants so avoid spraying on a windy day. Spot spraying when the weeds are young and during the heat of the day will give you the best results. Larger more established weeds may require a couple of applications.
A safe way to eliminate weeds without damaging your plants is to spread a layer of newspaper on the soil and then add a thin layer of mulch on top of the newspaper. This is not a process that will work overnight, but if you are willing to wait, it is easy, safe, and a good way to recycle your newspaper.
Corn gluten is another option. It is an organic pre-emergent herbicide that works great for eliminating future weeds by preventing the seeds from germinating. Unfortunately, it does not work for existing weeds.
Q Will you please suggest some plants or bushes for shade? —Sandra Price, Stanford
A As Kentucky gardeners, we have many shade-loving shrub options. Aucuba japonica, Mahonia, English Laurel (‘Otto Luyken’ and ‘Schipkaensis’), Pieris japonica, Taxus and certain azaleas are all great evergreen options. Deciduous shrubs to consider include: Oakleaf hydrangea, Bottlebrush Buckeye and Virginia Sweetspire.
Incorporating perennials and annuals among the larger shrubs creates a layered look as well as a range of color, texture, and depth. Although shade gardens can be extremely beautiful, they are not as full of flowers as sun-loving gardens. This is where the different color foliage comes into play. Some of my favorite shade loving perennials are Solomon Seal, Helleborus (Lenton Rose), Heuchera (Coral Bells), Brunnera, Bleeding Heart and several ferns including the Japanese Painted Fern. For a detailed list, click here.
Do you have height or width restrictions? It is always a good idea to measure your space before shopping for plants. Always space plants so they have enough room to mature without restriction. Visit the shade sections of your local garden centers to see what you can’t live without. From a design standpoint it is best to plant in groups instead of singles. Most garden centers have designers on staff, so take advantage if this is not something you feel comfortable doing yourself.
Q I have three bottlebrush buckeye plants in my shade garden. Two are dark and beautiful. The third starts out early like the others, but soon the leaves get yellow, rusty veins through them and dry around the edges. Does it need more water or nutrients? It is strange because it is next to the two healthy ones. —Sharon Thompson, Fisherville
A Bottlebrush buckeye (Aesculus parviflora) are lovely native shrubs. Best grown in part-shade and consistently moist but well-drained soil. This species of buckeye does not typically have insect or disease issues associated with other buckeye species, but from what you have described, there is certainly something going on with your shrub. Without seeing a sample, it is hard to say, but leaf scorch or leaf blotch are possibilities. For a proper diagnosis you should take a sample of your buckeye to the horticulture agent (Walt Reichert) at the Shelby County Cooperative Extension Service. The offices are located at 1117 Frankfort Road in Shelbyville. The phone number is 502-633-4593. Has this Buckeye lost any foliage? If so, be sure to remove and dispose of any fallen leaves. This will help prevent potential disease spread. I’m sorry I can’t be more specific, but I hope this will send you in the right direction.
Q I was recently given a clear plastic bag with 14 seeds and told they were Kentucky blue flowers. Someone mentioned you had done an article on them in the past. Can you tell me what I have based on this information? I need to know if they are perennials, how tall they grow and how much space to allow for them. The seeds look a little like tiny Oreo cookies, dark outside with a white filling you can see. I appreciate any help you can give. —Terri Duncan, Lexington
A From your “Oreo” description, it sounds to me like you were given purple hyacinth bean vine seeds (Lablab purpureus). These climbers are considered annuals for Kentucky gardeners, but the seeds can be harvested from their pods later this fall and saved for next year’s garden. At this point the seeds can be planted directly into the garden. Plant the seeds 2 inches deep and space them every 12 inches. The seeds should germinate within 7-10 days. Keep in mind that this vine will require a trellis, fence, or something vertical to climb on. Best grown in full sun and well-drained soil. Purple hyacinth bean will reach 10-15 feet in one growing season. The vine will begin to flower mid-summer and will continue to be a show stopper through the fall. Both the flowers and the bean pods will add color to your garden as well as attract butterflies, birds and bees.
Q Where can I purchase the “roll out the red carpet” roses that you talk about in the June issue of Kentucky living? Somewhere local if possible. —Judy Caudill, Florence
A Carpet roses are a great addition to any sun loving garden. Flower Carpet is a patented name sold by Monrovia. Within this series of roses there are several named roses. The business of naming plants can be confusing, and, just to be clear, the name is not “roll out the red” but simply Flower Carpet Red Groundcover Rose. Scarlet is another reddish rose in this series. As of June 16, Beaten Nursery and Greenhouse in Union had them in stock. I’m sure they would hold them for you if you want to call; their phone number is 859-384-4769. According to Monrovia’s website, these roses may also be available at Holscher & Hackman Plant Farm and/or Cassinelli’s Glendale Nurseries.
June 2015 IssueQ I have numerous yucca plants on my property and I need to know how I can thin them out. —Frederick Ward, Monticello
A Yucca filamentosa is typically what we see growing in Kentucky. These evergreens add a tropical feel to the garden and the sword-like, sometimes variegated, foliage adds interesting texture. Yucca are low-maintenance in terms of food and water. They have a clumping growth habit that over time will require thinning. From what you have described you have reached this point. Thinning out your plants involves removal of roots and foliage.
The challenge is removing the deep tap roots. Use a sharp spade to lift the plant and roots out of the ground; if any of the roots are left behind they might produce new plants that could require herbicide applications to eliminate. Depending on the amount of plants you are dealing with, it could take a couple of growing seasons to get them under control.
Be sure to protect your hands and arms when working with these plants. As you dig them up you will find many small individual plants within each clump. These can be replanted or discarded. Also, make sure you wear eye protection when working with yucca plants. You can easily get poked in the eye by the sharp, pointed blades, which can result in requiring medical attention.
Q How do I safely dispose of liquid Miracle-Gro that is about 5 years old? —Sally Thomas, Richmond
A According to the Miracle-Gro representative that I spoke with, the liquid plant food is best used within three years after being purchased if stored properly. It is still viable for up to eight years. Technically, it can still be used if you want, but if you prefer to dispose of it, you should contact your solid waste company to find out when they collect household chemical waste products. You may ask your gardening friends if they would be interested in using it before you dispose of it.
Q I have some mums that came up this spring and are almost a foot high. Do they need to be trimmed so they will “bush out”? —Deborah Brown
A Chrysanthemums, also known as mums, are a very large genus including annuals and perennials. They perform best when planted in full sun and well-drained soil. Depending on the variety that you’re growing, your chrysanthemum will begin blooming late summer or early fall. Pinching the foliage back is a good idea and will encourage a more compact growth habit, more stems, and more blooms. You can use a clean pair of gardening scissors or your index finger and thumb. Pinch back about 1 inch at a time. This can be done a couple times throughout the summer, but do not pinch back after the beginning of July. The plant needs this amount of time to produce blooms. Chrysanthemums are not heavy feeders, but will benefit from added nutrients before bud set. A half dose of your favorite fertilizer will be sufficient. Too many nutrients can actually prevent blooms.
Q I purchased a Stellar Pink dogwood tree early this spring. It is still completely void of leaves or flowers. The limbs and branches are green. I don’t want to plant it if it is a lost cause. I have kept it watered and in full sunlight, and I also protected it from our last frost. —Patricia Leone, Irvington
A It is concerning that your dogwood has not put on any new growth this season. Stellar Pink or Cornus x ‘Rutgan’ is a hybrid between the native (Cornus florida) and Japanese (Cornus kousa) dogwoods. This particular tree is part of the stellar series of dogwoods developed at Rutgers University. I mention its background because it is known for being vigorous and disease-resistant. Stellar Pink blooms after the foliage appears as opposed to the native dogwoods that bloom before new growth appears.
Given the timing of your question and where you are gardening, I would think yours should be in bloom. To find out if your tree has any life left, you can take a knife or fingernail and scratch the bark to find out if the cambium layer is green or not. If it is green, then it is still alive, but otherwise you may want to check with the garden center/nursery where you purchased your tree to find if it has a guarantee policy.
Q I have cattails growing in my ponds and behind my house. How do I get rid of them? —Kathy Jarrell, Sitka
A Although cattails (Typha species) can improve water quality and provide shelter for aquatic animals and birds, they are very aggressive plants and, given the right conditions, will quickly take over. You have a few different options in terms of eliminating them around your pond and home. The mechanical method will require a gas-powered weed eater or trimming tool. It will take more than one attempt, but removing the foliage will prevent the plant from absorbing essential nutrients and eventually the health of the cattails will decline.
The chemical method involves spraying the foliage with glyphosate. This chemical will kill the cattails, but it will also kill other plant material that it touches. The most common product that contains glyphosate as its main ingredient is Roundup but there are many on the market. Cattails have a waxy covering on their foliage so adding a surfactant to the glyphosate will help adhere the liquid and be more effective. It is best to spray before the seed heads form. As with any chemical application, always follow product instructions.
Muskrats are very effective in eliminating cattails. They feed on the rhizomes and a single animal is all you would need. I wish I could catch one for you from our pond! If you want to keep any cattails, it is best to keep them in submerged in nursery pots so the rhizomes cannot spread.
May 2015 IssueQ I have a lilac tree and a 3- to 4-foot branch just broke off. After I saw it off, should I brush or spray an ointment on the cut to prevent the tree from getting diseased? —Massimo Sabantini
A Before you prune out the branch that broke from your lilac, you will want to make sure that your cutting tools are sharp and clean. This will make it easier for you to make a clean cut and prevent any potential disease spread. You want to make your cut as close to the next intersecting branch or main trunk as possible but avoid cutting into the healthy wood. It is not recommended to cover or apply anything to the end of the cut. It is better for the tree to heal over on its own.
Annual maintenance will help lilacs in terms of vigor as well as overall appearance. Spring-flowering shrubs such as lilacs should be pruned immediately after they have finished blooming. Dead or diseased branches should be removed as soon as you notice them.
Lilacs will also benefit from being thinned, which means removing some of the older, woodier branches. This is especially true for the center of the plant, which can become dense and does not allow for good air circulation or filtered sunlight. Both can lead to disease problems.
Q I need advice on planting my potatoes. I haven’t cut them yet, and I have a bag of organic fertilizer. What do you suggest? —Kathy Daulton, Frenchburg
A It’s potato planting time! It may or may not be necessary to cut your seed potatoes. If you purchased large tubers, then these should be cut into pieces. Small seed potatoes can be planted whole. Any tubers larger than a chicken egg should be cut into pieces. Each piece should have at least two eyes/sprouts. You can either cut as you plant or prep them a few days before planting and allow the new pieces to callus over.
Potatoes benefit from a nutrient-rich, well-drained soil. If you have not added compost, this may be a good idea. Follow the application rates of the fertilizer that you have. Plant your seed 2 to 3 inches deep and 12 inches apart. It will take three to four weeks for foliage to appear; once it reaches 4 to 6 inches tall, it will be time to add soil or straw to protect the developing tubers. Be sure not to cover the foliage at this stage. Harvest a couple of weeks after the foliage dies back or any time after they bloom.
Q We have an approximately 8-year-old Southern Magnolia tree that has done well in the past. This spring, it has lost almost all its leaves, and I don’t see any buds or new growth. We live in northern Kentucky. The leaves turned brown and fell off. We aren’t sure if the bitter cold this winter has killed it or if there is a chance it will come back. We hate to lose it, as it is about 25 feet tall and a great addition to our landscaping. Any suggestions would be greatly appreciated. —Karen Daniels, Alexandria
A Even established trees can be injured during extremely cold winters. Southern Magnolia (Magnolia grandiflora) is no exception. We had prolonged periods of no snow or moisture combined with freezing temperatures, and for evergreens, this can be a recipe for disaster. This is especially true if your magnolia went into winter without sufficient moisture.
Even though magnolias thrive in full sun, they benefit from being planted near a structure for the reflected heat. It is also best to avoid planting them in low-lying areas of your yard where they will be exposed to the coldest air. Intense winter sun can cause the foliage to burn and drop. I think you are correct in your assumption that the winter hits damaged your tree. At this point it will be a waiting game, but if it does not put on new growth in the next few weeks it likely will not at all. I wish I could give you more optimistic news.
Q I have a peony with a white coating all over its leaves. It’s as if it were a mold, but it sits out directly in the sun. What is it and what can I do for it? —Teresa Cammack, Boston
A It sounds like your peony has powdery mildew. This fungus is more prevalent when the weather conditions are right. Humid, warm days followed by cool nights are ideal conditions for these spores to spread. Like all other ornamental plants, peonies are more susceptible to powdery mildew if they are watered overhead, over-fertilized, and/or do not have sufficient air circulation.
The good news is this fungus will not harm your peony. Aesthetically, it looks bad, but it will not have any negative effect on the overall health of your plant. These spores can over-winter in the surrounding soil or mulch so it is important to remove all infected foliage. As a preventive measure, a registered fungicide can be applied at the first sign of this fungus. Horticultural and neem oil can be effective in mild cases after the fungus is present. Always follow product application rates when using controls. If your peony is unsightly, it is best to remove and discard all infected foliage. It’s also a good idea to disinfect your cutting tools to prevent disease spread. I hope you got to enjoy the blooms before the fungus appeared!
April 2015 IssueQ I have leftover Miracid and Miracle-Gro from last year. Is it good this year? —Jane Pyle, Maysville
A The answer to your question depends on the form of your plant food. Powder-based fertilizers should last for several years if properly stored in a dry space at room temperature. Liquid fertilizers, on the other hand, have a shorter shelf life and should be used within two years of purchase. Ideally, they are stored at room temperature, between 60 and 70 degrees. If liquid fertilizers are subjected to drastic temperature changes, especially freezing temperatures, this can cause separation, changing the chemical composition of the product.
Plant food comes in a variety of different sizes in granular, water soluble, and liquid form. You usually get a better price if you purchase a larger quantity, but if it is not going to be used within a season it really is best to buy the smaller size and start fresh each growing season. That way there is no guessing about whether your plant food is still viable.
Q We bought a 50-year-old house with an overgrown lawn and garden. I am trying to transplant a bunch of pink “magic lilies” before their foliage dies back and I lose track of their location. They are planted individually, so I am trying to condense them. As I’m digging up the ones that bloomed, I am running into a lot of bulbs in the same hole that didn’t bloom, but look as they are still viable: the bulb is fleshy and white inside and the roots are there and white. Are these worth replanting? —Susan Flowers, Louisville
A Lycoris squamigera, also known as surprise lily, naked lily, resurrection lily, and/or ghost lily, is a summer flowering bulb that belongs to the amaryllis family. These bulbs are an old-fashioned favorite that are considered very low maintenance. They can multiply quickly and tolerate most growing conditions, but will bloom best if grown in full sun. Because these bulbs multiply so quickly they benefit from being dug up and separated every few years. From what you have described, you have a lot of bulbs to dig up and replant. As long as the bulbs are still viable it is worth the effort of transplanting them. They definitely will look better in a mass planting as opposed to planted singly.
When the foliage dies back is the time to dig them up and move them. The smaller bulbs may not bloom well for the first couple of years but will eventually produce large flowers. The bulbs should be planted 4-6 inches deep and each individual bulb will grow about 2 inches wide so keep this in mind when planting.
Q What do I need to do to get my Gerbera daisies to bloom? They look healthy but no blooms! —Sharon McHugh, Dry Ridge
A Gerbera daisies provide vibrant color in the summer garden. Each plant has different growing requirements and Gerbera daisies are no different. They prefer to grow in full sun, which means they should receive six hours of sunlight each day. These annuals prefer moist, well-drained soil. It sounds like your plants are very happy but may need some encouragement to produce more blooms. Have you fertilized lately? Our annuals benefit from a weekly liquid food, or if you prefer a granular, slow-release food that only needs one application per season. Over fertilizing can have the reverse effect in terms of flowers so it is important to follow recommended application rates for the product you are using, either granular or liquid.
Gerbera daisies are subject to powdery mildew, a fungal issue. Ideally watering should be done in the morning or afternoon while the sun is still out and the foliage can dry off before nightfall. When we water at night the foliage does not have a chance to dry off and fungal problems are more likely to occur. A well-balanced fertilizer such as 10-10-10 will be sufficient. For now, remove all spent blooms, water well, feed, and wait. Your daises should produce new flowers soon.
Q I have a crape myrtle and it’s got new growth coming up from ground; when do I cut off the old limbs from last year? —Joyce Snook, Smithfield
A This past winter was unusually cold and plant material on the edge of our hardiness zones, including crape myrtles (Lagerstroemia), were not happy about it. A lot of them died back to the ground, but just as yours has done, they have put on new growth from the roots. You can remove the dead wood back to the base of the plant and eventually the new growth will grow to the same size as the original plant. Pruning out the dead wood will give the crape myrtle a tidier appearance and allow for better light filtration. If the dead wood is left on the plant it can become a nice home for insects to live. Hopefully our gardens and we will not have to endure another winter like the last one but if we do, in late fall apply a 2- to 3-inch layer of mulch to help insulate the roots.
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