I like English ivy — in the right place.
To a non-gardener, that doesn't sound like much of a confession. But to gardeners and people who enjoy walking in the woods, those are fighting words.
English ivy (Hedera helix) leads invasive plant lists in many states. Imported centuries ago as an ornamental vine, the plant has become a dark green thug in American woodlands, covering the ground, crowding out native plants and sometimes killing trees by blocking sunlight. On buildings, it can ruin mortar, wood and any type of siding.
And yet it is one of the very few evergreen groundcovers that will grow in complete shade.
Hedera Etc., a mail-order nursery in Lionville, Pa. (1-610-970-9175), sells more than 400 varieties of ivy organized into categories such as bird's foot, curlies, fans and heart-shapes. Less hardy and invasive than the species, these ornamentals are favorites in beds and containers.
When I moved to the South Hills area of Pittsburgh nearly 20 years ago, I found the common variety of English ivy growing on a steep slope from my driveway down to the back yard. Other than a single peony bush, it seemed the only thing that would grow in the shade of a half-dozen 60-foot Eastern white pines and Norway spruces. It had begun to creep up the trunks of these huge evergreens and, not knowing any better, I let it go. I decided it looked better than the white sap that dotted the ground and trickled down the trees' trunks.
Although a few visitors told me ivy could hurt trees, I didn't find out exactly how until I became the Home & Garden editor five years later. By that time, I was an ivy lover. I had let it grow up the pine trees that the previous homeowner had built a deck around. I applauded when it quickly filled a slope left bare by the excavator after we had an in-ground pool installed. And I wove ivy through three sides of the black chain-link fence surrounding the pool. Within a few years, the fence was a solid green wall, giving us privacy.
Until this year. The one-two punch of a dry, mild fall and cold winter killed most of the ivy on the fence. But it also provided a surprise — lots of odd little flowers on the ivy covering one of the trees by the deck.
I first saw these clumps of greenish-yellow flowers on ivy growing in Georgene Albrecht's garden. Albrecht, who won honorable mention in the Pittsburgh Post-Gazette's Great Gardens Contest in 2005, gave me some clippings, which I planted by a garage wall. Four years later, they were doing well but have never bloomed.
Two years ago, I had noticed a clump or two of ivy flowers on the tree by the deck. An Internet search revealed that mature English ivy sometimes puts out flowers and berries and becomes more shrublike. Some leaves change shape from three- or five-lobed to spear-shaped. (To see better photos of mature ivy leaves, flowers and berries, go to www.weedsbluemountains.org.au/english—ivy.asp.) As flowers go, they're not much. But they are a neat little conversation piece.
Now for the disclaimer: Don't grow English ivy if you live anywhere near woods or other public land. Also, it's not something you can plant and forget. Neighbors don't appreciate it in their flowerbeds and it really can kill trees, especially deciduous ones.
On pines like mine, it doesn't seem to stray from the trunk. I figure as long as I keep cutting the ivy back about 20 feet up, I can have my trees and ivy, too. Beneath the pines, I've been ripping out ivy to make room for hostas, ferns and other shade lovers. And other than the tiny patch of ivy I got from Albrecht, I've found other, better-mannered vines to plant by the house and deck, including climbing hydrangea, clematis, roses and golden hops.
Distributed by Scripps Howard News Service