Ivy has to be one of the most widely recognized plants for gardeners and non-gardeners alike. Everyone knows what it looks like and it is just one of those plants you either love or love to hate.
The ivy that everyone is so familiar with is good old common English ivy, Hedera helix. Popular as ground cover, this hardy ivy will also climb and can also be considered a vigorous climbing vine. There are more than 400 cultivars of English ivy identified, but just a few dozen are commonly available. Keep your eye out because while the majority are hardy, there are many gaining in popularity that are not.
The non-hardy English ivies make great houseplants, as do Algerian ivy and several other varieties. Small pots and hanging baskets to bonsai tree forms and topiaries of all shapes can be seen on the pages of every interior design magazine I pick up. Ivy planters can be used as an accessory or accent piece in almost any room of the house.
So what environment does this popular and versatile plant like? Ivy is really not that picky and will grow successfully in alkaline or acidic soils, but generally prefers alkaline. It can be seen prospering in sun or shade but is more commonly grown as a ground cover for a shady area. This ability to grow in a dark or shady spot has contributed to its success as a houseplant where light levels are typically low.
Adequate moisture is critical during establishment. Most ivy is planted as a ground cover under trees where it is both shady and dry due to root competition. In this case a good soaker hose will more than pay for itself by keeping the new planting adequately moist and preventing the need for replacing ones that have died.
When grown as a houseplant, keep the potting mix and root zone evenly moist. This keeps the plants looking their best and reduces stress that can aggravate a host of insect or disease problems known to affect ivy. Spider mites are the biggest pest of houseplant ivy, so maintaining a healthy vigorous plant is your best defense.
The controversy of whether ivy growing on walls or surfaces is damaging to them or protects them still rages. It has been growing on all kinds of surfaces in England and in the eastern United States for 100 years or more and no damage has been reported. My general advice is when any climbing vine is growing on walls or fences, it should be kept trimmed away from any windows and doors, as well as gutters and rooflines; otherwise, let it climb and enjoy.
Only a few hardy English ivies are commonly available in our area. It is important to note the exact variety you plant in case you ever need to replace a few. Some may appear to look the same in the garden center but when you get them home they may not match at all. Plain English ivy (no cultivated name) is the easiest to find, and is typically used when large numbers of plants are needed because it can be the most economical. The shiny, dark-green, heavily veined evergreen leaves are typically 2-3 inches long and equally wide.
A few hardy cultivars to look for are Baltica or Baltic ivy. It has smaller leaves than the straight species but has been proven not to be as hardy as they thought. Reserve this plant for a protected site. Thorndale is the most common cultivar of English ivy and has proven itself as the hardiest. It has slightly larger leaves than the species with less predominant lobes and veins, making for a smoother leaf.
One of my favorite non-hardy varieties is Algerian ivy. Its large, smooth leaves are a refreshing change from the heavily veined English ivies. The variegated version is very attractive and makes an impressive addition as a houseplant or in an annual combination container for the summer. One very popular ivy, H. helix ‘Glacier,’ is getting all the press. It has been featured in several gardening magazines over the past year or so. The small 1- to 2-inch leaves have a lovely thin, white variegation on the edge and can have a slight red to pink hint to the edge of the leaf. The popularity of non-hardy ivies is really taking off, so we will start to see more and more cultivars available to us over the next few years.
Ivy is a welcome addition to my garden both inside and out. I will continue to enjoy my plain old English ivy as it sprawls and climbs throughout my garden. I am careful to not let it take over, smothering out my perennials, shrubs, or ground covers that are an important part of my design. The extra effort is certainly worth it for the weed suppression the ivy provides.
If you haven’t tried growing ivy, give it a try. Try out a few hardy and non-hardy forms as they become available. Place them in your annual container gardens and test them out as houseplants. Healthy, vigorous potted ivy is always welcome in my kitchen.