English ivy (Hedera helix) is native to Europe, western Asia and Northern Africa. Plants were introduced in the United States for their ornamental properties. There are over 400 varieties of English ivy, with a wide variety in plant types and characteristics. The species is categorised as an evergreen, meaning the plants maintain their foliage all year instead of shedding their leaves. Because English ivy plants can grow aggressively and invasively, shading out deciduous native plants, they are considered as a problem in certain states, most specifically in wilderness and forested areas.
The American Ivy Society categorises ivies under a system called the Pierot System of Classification, developed in 1974 by Suzanne Pierot, President of the society. The Pierot System classifies ivies based on the plant's leaf shape and type. Classifications include variegated ivies, bird's foot ivies, fans, curlies, heart-shapes ivy, ivies with five-lobed leaves, miniature, adult, and oddities, which covers a species with unusual characteristics such as having oddly-shaped leaves, growing erect or being a non-vining ivy.
Climbing vines often come to mind when the look of English ivy is visualise. If you are looking for a plant type to attach to masonry such as brick home or building, there are many varieties to choose. For a traditional dark green look, consider varieties such as Persian Ivy with its heart-shaped leaves that can grow as long as 10 inches; Baltica to climb trees and structures with leaves that change from deep green to bronze-red in winter. Plant types proven to be cold-hardy include Ogalalla, Bulgaria and Baltica, known for its ability to climb leaves and structures with leaves that change from deep green to bronze-red in winter.
While English ivy is often thought of in terms of as a climbing vine, there are also varieties that you can select for a ground cover. One popular choice is Manda's Crested, for its ruffly pea-coloured leaves that can grow up to 4 inches wide. Another good ground cover choice is Compacta erecta, with pointed, three-lobe green leaves. Ivalace leaves maintain "juvenile" characteristics, only reaching an inch or so in length and can be used as a zeriscaping alternative to growing a grass lawn.
Variegated Leaves and Seasonal Color
While the evergreen-look of dark green English ivy is classic, don't overlook varieties that offer options for variegated leaves and variations in seasonal colour. Buttercup climbs structures with leaves that range from yellow to chartreuse. Purpurea leaves start off purple and turn to darker or change to bronze during the winter months. Many varieties include variegated choices. Silverdust is a fast-growing variegated variety that combines traditional green colours with wisps of creamy white striping. The variegated cultivar of Algerian ivy provides garden interest with huge, shiny green and white striped leaves that can span from 5 to 8 inches in width.