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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