English Ivy (Hedera helix).
English ivy will always be a favorite among gardeners and yardeners alike for its versatility. It is easy to grow, forms an excellent dense groundcover in shade where grass struggles and remains green all year, bringing color to the winter yard. Given the slightest encouragement, it also climbs walls, trellises and trees. Because it tolerates air pollution and poor soils, it is ideal for urban settings. English ivy varieties vary in their cold tolerance but they are typically winter hardy where temperatures fall to -20° F (Zones 5 to 10), farther north with some protection.
Contrary to common belief, English ivy does not kill trees if it is allowed to cover their trunks. However, it will eventually damage stucco walls or old grouting between bricks or stones. A naturally occurring compound in its stems, leaves and fruits may cause contact dermatitis in susceptible people.
Size: When grown as a groundcover, English ivy spreads wherever it’s allowed, and forms a dense mat 6 to 8 inches tall. As a climbing vine, English ivy uses its root-like holdfasts to ascend up to 80 feet, often completely covering walls.
Foliage: English ivies have two distinct kinds of foliage. “Juvenile” leaves are typical in most plants, which are usually in their creeping or early climbing stages. These tough, leathery, evergreen leaves have 3 to 9 lobes and are up to 6 inches long, depending on the variety. They are usually dark green, but some varieties have leaves that are light green, gray-green, or variegated yellow, white or silver. Later, “adult” leaves develop as the plant achieves some height and stability. Adult foliage usually is not lobed. Leaves and stems are coated with fine, fuzzy hairs. In rare cases, these hairs or the plant’s sap may cause a rash when the plants are handled.
Flowers: Ivy plants grown, as groundcover almost never flowers or fruit. Five-petaled greenish-white flowers appear in inconspicuous nodding clusters only on mature plants in September or October. Small black berries in mild climates follow these the following spring. The berries occasionally become a nuisance if they seed into neighboring plantings. They are also reputed to be toxic.
English Ivy Choices
While there are 6 other species of ivy, most of the estimated 300 known ivies are versions of English ivy. They are all sizes, growth habits, leaf forms and color.
Some interesting types of English Ivy are:
‘Baltica’ is very hardy, with small leaves and whitish veins.
‘Buttercup’ is a climber that has striking chartreuse or yellow foliage; excellent for dark corners.
‘Compacta erecta’ is a non-climbing form featuring 3-lobed, pointy green leaves with gray veins.
‘Goldheart’ is a beautifully variegated green and yellow selection with 3-lobed leaves and pink stems.
‘Hibernica’ is quick growing, with large, shiny leaves. Now recognized as a separate species, Hedera hibernica, it is widely used.
‘Ivalace,’ also known as ‘Wilson,’ has delicately crinkled leaf edges.
‘Manda's Crested’ is one of the premier groundcover ivies, with elaborately-ruffled, 5-lobed, pea-green leaves almost 4 inches in diameter.
‘Ogallala’ handles cold well, but not drought.
‘Tree Top’ has entire, smooth-edged leaves characteristic of “adult” ivy.