English ivy, Hedera helix, is a plant loved and hated by many, a valued garden ornamental and a destructive pest, especially in mild winter areas. Native from Asia to Europe and from Scandinavia to northern Africa, it grows in the wild as a creeping groundcover in part to full shade. Growers have developed over 400 varieties, some streaked with yellow or white, some growing only a few inches tall and others with gray- or purple-veined leaves.
As a tough groundcover, English ivy has few equals. It can endure poor soil and a certain amount of drought, when established. It flourishes in deep shade as well as part sun, growing among tree roots where other plants fail. It clings to wood, bark, stone and cement with small rootlets, climbing up fences, walls and tree trunks and covering stumps. This makes it a valued vine for covering unsightly objects in shady areas.
As a container plant, it can serve in hanging baskets and window boxes. It softens the edges of large pots, giving a green background for bright flowers such as impatiens. Many varieties make excellent houseplants, flourishing in the poor light of north or east windows.
Ivy should be planted a foot to two feet apart as a groundcover or climber and watered well the first year or two to give the root system time to develop. This is particularly important in cold winter areas where it may be marginally hardy. No special soil preparation is needed.
Indoors, give it a cool room, 45 to 60 degrees, and regular watering. Allow it to dry slightly between soakings, however, as it does not like constantly wet soil.
English ivy is easily propagated from cuttings or from rooted pieces of the runners that spread across the ground. Take cuttings in fall, dipping them in rooting hormone powder and placing them in a mixture of sand and peat or in regular potting mix.
The rootlets that give English ivy its ability to climb can also damage the surface of walls and fences, and the shoots can push under and around boards and siding.
The climbing vines can overwhelm trees, causing branches to break and making the tree more vulnerable to wind damage. While it may stop short of engulfing the tree entirely, it can climb over all but the very top shoots.
As a groundcover, it can spread widely and thickly, destroying habitat for native plants. The seeds are easily spread by birds.
Small areas of ivy can be removed by hand, the climbing vines torn down and cut off at the base and unwanted areas of groundcover dug up. Very tall vines, whose trunks may be six inches or more in diameter, can be cut at the base, leaving the tops to die. A systemic herbicide or brush killer may need to be applied to discourage resprouting. Ivy covering large areas may need to be sprayed with a foliar herbicide to avoid digging up the ground more than necessary.