English Ivy: Friend or Foe?
English Ivy is a popular landscape plant, but it must be properly maintained to prevent it from becoming an invasive plant.
English ivy, Hedera helix, has been a popular landscape plant in the United States since colonial times, and it is used frequently as a ground cover in many yards in the Severna Park area. It is a hardy, long lasting plant, and its dark, glossy green leaves often provide a contrasting background for other plants in the garden. In this area, it is easy to find English ivy growing up the trunks and branches of trees and carpeting the ground around the trees on public and private land.
Unfortunately, due to its ability to grow well in a variety of conditions, English ivy is now considered an invasive species because it has become established without being intentionally planted, especially in wooded areas.
The Plant Conservation Alliance states that English ivy “spreads locally through vegetative growth and is dispersed longer distances via seed which is carried to new areas by birds… including the Cedar Waxwing, Northern Robin, Stellar Jay, Mockingbird, European Starling, and House Sparrow.” It can also be spread by dumping ivy cuttings in wooded areas, where the cuttings can take root and become established.
The problem with this plant growing unchecked is that it destroys the habitat of native wildlife since it eventually kills the trees on which it is growing and prevents adequate light from reaching native plants that grow on the ground in woodlands. It also does a poor job of controlling soil erosion because its roots are shallow.
The Plant Conservation Alliance warns that when trees are covered with English ivy “the added weight of the vines makes infested trees much more susceptible to blow-over during high rain and wind events and heavy snowfalls.”
However, according to The National Arboretum, English ivy can be successfully used as a landscape plant if it is properly maintained. By pruning regularly and not allowing it to grow on a vertical surface, which causes the plant to mature and form seed, English ivy can be prevented from spreading beyond the borders of a garden.
The Plant Conservation Alliance recommends several methods of controlling the unwanted spread of English ivy through manual and herbicidal means. Homeowners can keep this plant under control by manually trimming it along garden borders, from around the base of trees, and not allowing it to grow on any vertical surfaces. Any cuttings should be bagged and disposed as garbage. The Plant Conservation Alliance also recommends several ways to control or eradicate English ivy by chemical means if the infestation is too severe to be managed by trimming.
While English ivy is considered an invasive species, it can still be purchased at garden centers and continues to be a popular landscape plant due to its durability and attractive foliage. The key to successfully using English ivy as a landscape plant is to control its growth and properly dispose of any cuttings.
Both The Plant Conservation Alliance and The National Arboretum have recommendations for native plants that can be used in place of English ivy.
Tina by the Bay
10:26 am on Tuesday, March 27, 2012
English ivy is great for topiaries specially the varigated ones. The concern that I see in my neighborhood is that when people get tired of the potted English Ivy, they dump them by a common wooded area. Left unattended, the ivy becomes a problem.