Filed under: Invasive plants. Tagged as: English ivy, hedera helix, invasive plants, npr, shade plants, washington dc.
People blessed with shady gardens often feel stumped about what to plant, so they turn to English ivy (Hedera helix). English ivy is inexpensive, fast-growing, and easy to care for. Unfortunately, it is also invasive.
It quickly crowds out desirable vegetation on the ground. Worse, it also climbs any vertical surface, including your trees and your home. English ivy climbs with tiny roots that exude a chemical that breaks down the surface upon which it clings. This is bad news for your home (despite the romantic image of ivy-covered cottages) and deadly news for your trees. English ivy smothers the tree’s own leaves, causing entire large branches to die. Eventually, English ivy weakens the tree and kills it, creating a safety hazard. It also takes away from the beauty and the balance in the ecosystem of a mature tree. It takes decades for another tree to grow to replace it.
Invasive plants do not respect the boundaries of your fence, so your English ivy becomes your neighbors’ problem as well. Birds also help to spread English ivy to nearby woods where it quickly smothers native ground vegetation, eliminating animal food and habitat, then starts work on the trees.
How do I get rid of my English ivy?
First rescue your trees. Cut all of the vines at the base of the tree. Make a second cut about two feet above the first. Carefully remove those pieces of vine without damaging the tree bark. Do not try to tear the vines high up in the tree. Cut off from its roots, the ivy will eventually die and fall from the tree on its own. Next, pull out ivy on the ground to create a clear space around the tree at least six feet in diameter so that it doesn’t grow right back up the tree.
On the ground, carefully cut ivy away from native plants, then pull up the ivy with its roots. You will need to check back over time to make sure that the ivy does not regrow from pieces of root left behind.
But I need a shady groundcover. What do I plant instead?
Groundcover need not be a vine. Plant a sweep of native ferns such as Adiantum pedatum, (Northern maidenhair fern) or Polystichum acrostichoides, (Christmas fern) beneath your trees. The lacy fronds give an airiness to your shade garden and you can watch the fiddleheads unfurl each spring.
Or try Asarum canadense (Wild ginger). It is very low-growing with heart-shaped leaves and it slowly spreads by underground stems. Mitchella repens (Partridgeberry) will provide fruit for wildlife as well as groundcover. Chrysogonum virginianum (Green-and-gold) has small yellow flowers.
You can simply place 2-3 inches of mulch beneath your tree all the way to the drip line. The next time you take a walk in the woods, notice that Mother Nature leaves space among the plants. You do not need to fill every inch, right up to the trunk of each tree.
Even the English recognize that English ivy has no place in this region. The English ivy has been removed from the British embassy residence garden in Washington, DC.
How do I learn more?
Invasive Plants: Weeds of the Global Garden published by Brooklyn Botanic Garden