There are many evergreen ground covers for the shade garden, but not so many that are tough, vigorous and capable of covering large areas quickly. Behold the English ivy, a woody vine that has entwined itself into history, myth and the carport.
It has other practical attributes: It will hold sloping soil against erosion and – unlike other ground covers – it doubles as a self-anchoring climber that will soften bare walls and hide plain fences.
But now the ivy has fallen on hard times.
Ivy was invaluable when gardens were more static, tidy and architectural, but it was eclipsed by more interesting ground covers by the end of the 20th century. Thus ignored, it decided to make mischief.
Untended for long enough, the ivy will clamber to the top of a tree and from its high perch transform itself into an evil twin. Aloft, its distinctive foliage shifts to a paddle shape. In the autumn, the clusters of little white flowers draw bees from afar and then spend the winter turning into black berries. Birds devour them and spread them into the wild. Thus seeded, the ivy begins its patient journey of conquest.
But there is a way to pull ivy vines from trees.
This is done by cutting the vines that cling to the trunk at shoulder level and at ground level, using pruning saws and loppers. Often the severed segments have to be pried, carefully, from the tree using a crowbar, said John Maleri, programme manager of the Rock Creek Conservancy.
You can (and should) do this at home, but don’t rip down the vines immediately. They take a few weeks to die and wither, and it then takes a hard freeze to get the aerial roots to release their grip. At that point the vines either fall or can be tugged down without harming the tree.
What is the problem with English ivy in natural areas? On trees, the sheer mass of the vines can help bring down the host in storms. Ivy also blocks sunlight that trees need to feed. Aesthetically, it’s hard to love the look of a tree cloaked in ivy, unless you’re into Gothic horror.
If you have ivy as a ground cover, the simple act of keeping it in bounds with occasional clipping will stop it from spreading. On a wall or fence, the same maintenance approach will work. If it is growing up a tree, remove it.
Note: The English ivy is a NEMBA Category 3 invasion species in South Africa
Text Adrian Higgins Photography The Washington Post