For the Love—Or lack Thereof—Of IVY!
Q. Mike: I have ivy beds around my property. I believe they are English ivy. They were in bad shape when I moved in and are getting worse; weeds are starting to take over! I try to pull the weeds out by hand, but some of them have a well-established root system. Is there a way to kill the unwanted plants without harming my ivy? And what should I do in terms of long-term care to make the ivy thrive? Thanks so much,
- ---Andrea in Rose Valley, PA
A. Russ Windle, Director of Research for the American Ivy Society, explains that "English ivy" is a common name attributed to lots of vining plants, including many that aren't true ivies of any kind. So you might want to visit the Society's fine website and make sure that your English Ivy IS English Ivy.
No matter what it is, you have two basic choices. One is to dedicate this season to beating the weeds while not stressing the ivy. Repeated cutting of the top growth or pulling the main part of the plant out of the ground eventually exhausts the root system of even the most tenacious weeds.
Get a flame weeder and occasionally torch the unwanted plants in between pullings and cuttings. Just be careful not to torch poison ivy (one of the many not-true ivies); burning those leaves gets you a free trip to the emergency room. Or carefully spray the unwanted plants with an herbicidal soap. Any soapy overspray would run off the waxy leaves of true English Ivy.
Soap and flame achieve the best results when the plants are bone dry and, if possible, stressed by full sun. You'll find lots of details in our Question of the Week, "Whacking weeds with soap flame and vinegar." Pulling weeds out by hand should only be done when the soil is WET.
Your other option is to rip out everything in those beds and root the ivy pullings in big pots in the shade (if it IS English Ivy, the cuttings will root without any encouragement from you; just keep them cool and shady. And well-watered, especially in the beginning). Then clean out all the weed roots and replant the Ivy. Do not replant ivy in summer if the beds get a lot of sun; wait till the fall to replant and the unstressed ivy will thrive and hopefully out-compete any weedy remnants.
Or replant fresh with one of the highly ornamental varieties out there. Here's a great "which ivy should I grow?"
Q & A from the American Ivy Society.
And finally, the basic care of true English (or "common") Ivy (Hedera helix for our Latin lovers out there) is beyond easy. These plants can tolerate a wide range of temperatures and soil pH, grow in sun or shade, and although they like a little Nitrogen fertilizer every once in a while, can survive decades without being fed. Ivy's only real enemy is poor drainage, which eventually rots the roots.
Q. I'm trying to get rid of English Ivy. Can you recommend something more friendly to the environment than the Roundup my husband put down last year? (It didn't have much effect anyway.) Or that can kill it once and for all? The English Ivy produces small purple flowers in the spring, and I've heard that it's more vulnerable to chemicals during this flowering stage. I've also heard that ivy is fierce and keeps coming back. (We've been in our house for one year; I guess you'd call last season "Round 1".)
- ---Tammy in Silver Spring, MD
Q. Well Tammy—the good news is that you don't have any kind of true ivy, including English Ivy, as the small insignificant flowers of Hedera species are green and appear in the Fall. I personally have several purple flowered weeds in my landscape right now that have 'ivy-like' leaves, but I don't consider them a problem, as they're luring pollinators to my wife's blooming peach trees and soon-to-be blooming raspberries.
Try and find your plant on a weedy website or call your local county extension office with a sample plant in front of you. If it's creeping Charlie (aka "Ground Ivy"), follow the directions in our Question of the Week on that wascally weed. If the leaves have a waxy coating, you'll have to torch the plants with a flame weeder, pull the roots out of wet soil or cut the vines to the ground and soak the roots with a high-strength vinegar.
And be patient—few gardeners score a knockout in the early rounds against established weeds; they have great Cut Men in their corners.
Q. The woods next to our house are being completely covered by ivy. It began as a houseplant that was thrown into the woods. Now it has taken over the ground and climbed the trees. The ivy has overwhelmed our brush and is killing off poison ivy, which is good, but more important to me is: "Will the ivy kill the trees?" Thank you,
- ---Sandra on Lake Livingston in Livingston Texas
Q. Ha! Now that's the ivy we know and love! Yours sounds like Hedera hibernica, or Irish Ivy, says Russ Windle, who explains that this plant is MUCH more aggressive than English Ivy, although it is often misidentified as the English species. Anyway, the American Ivy Society does not feel that Ivy kills trees. Ivy is epiphytic (it just holds onto surfaces) not parasitic; and it doesn't seem to cover the canopy enough to block light to the tree leaves. But some arborists feel that thick stands of climbing ivy can harm trees, by keeping the ivy-covered trunk constantly moist. So just thin the vines occasionally to make sure the bark gets enough airflow to stay dry.
Q. Mike, how do I get rid of ivy? It covers my yard and fence. Thank you!
- --- Kathy in Manassas, VA
Q. Well, as we've been saying, first try and make sure it IS ivy. If it is, forget about pinning your hopes on chemical herbicides like the frog-and-toad killing, female-hormone-disrupting, Parkinson's Disease-causing Roundup Tammy's husband foolishly sprayed a few questions back. Liquids just roll right off of ivy's waxy leaves.
If the leaves aren't waxy, try cutting the plant back to the ground and then attacking the re-growth with a couple rounds of herbicidal soap or high-strength vinegar sprays on hot, dry sunny days. If the leaves have a waxy coating, you'll have to torch the plants with a flame weeder, pull the roots out of wet soil or cut the vines to the ground and soak the roots with a high-strength vinegar.