Question: About 5 years ago, I planted a tough, low maintenance ground cover on a hilly, partly shaded section of my landscape. It worked well as it spread, holding the soil in place very nicely, and looked pretty and green year round. In the last couple of years, however, it has become a bit too assertive and is now climbing trees at the edge of my yard. What are the “pros” and “cons” of ivy, and could it potentially damage my trees?

Answer: Ah, the love/hate ivy conundrum! Yes, for many years we’ve planted and encouraged ivy to “boldly grow where no plant has gone before” and in many cases it has succeeded – too well. Ivy (Hedera helix is the English Ivy commonly found in this area) was introduced from England, Europe, and Asia in colonial times. Initially planted as an ornamental vine, we still see it covering the walls of stately historic structures as well as more modern homes and buildings. Its year-round greenness attaches not only to brick, it is a frequent inhabitant of urban forests, to the dismay of urban foresters whose task it is to keep the vine in bounds.

In comparison to other aggressive vines such as kudzu, ivy tolerates greater amounts of shade, enabling it to win against some pretty tough competition. In fact one of ivy’s “charms” is that it can grow where other vines cannot, one reason for its listing in the “Invasive Plants in Southern Forests” field guide.

So aside from its year round coverage of shady spots in the landscape, under trees, or on sloping, hilly land where erosion is an issue, why plant ivy in the first place? It attracts little wildlife other than rodents (rats, mice) and in our part of the state snakes have been reported slithering through its matted roots. Its seeds or drupes appear pale green in August, becoming a dark blue in February and March, but are only moderately attractive to birds and other seed-eaters. In fact, the fruit is considered somewhat toxic to humans, and some individuals with sensitive skin can develop contact dermatitis if exposed to the vine.

As mentioned earlier, ivy likes shade, is also successful in moist open forests, but is highly adaptable, even growing on rocky cliffs. It does not do well in wet areas but in ideal conditions, grows aggressively once established. Infested trees can experience a loss of vigor, and English ivy can serve as a host for bacterial leaf scorch that infects oaks, elm, and maples.

English ivy should not be confused with “Poison” ivy (Toxicodendron radicans); the two are not in the same genus. However the familiar warning “leaves of three, let it be” can be confusing as leaves of juvenile ivy have 3-5 pointed lobes. The poison ivy’s stems are quite hairy, and its leaves drop off during winter.

Since there is the potential for ivy to cover branches, preventing leaf-out, and eventually smother them, should you remove it from your trees? The short answer is “Yes.” That does not necessarily mean you must get rid of ivy that is performing adequately in the area, but it does mean regular monitoring and action to keep the sneaky vine from re-emerging and lacing up its climbing shoes!

One approach to taming ivy’s spread and to prevent it from menacing trees in the landscapes is to “clear and cut.” Cut a circle of ivy away from the tree trunk, either via weed-eater (careful that we don’t get too close and whack a tree trunk), hand-pulling, or with a lawn mower. In addition, using hand pruners, loppers or a hand saw, remove a section at least 12” tall all the way around the trunk at base of the tree. The ivy that is now hanging from the tree by virtue of the 12” tall section that was removed will dry up and fall from the tree, or it can be pulled out by hand. Be careful as that vine can be up to 90’ long, and you may be yanking one that has crawled to the tree top. Then starting with the circle you removed earlier, extend that cleared area to a 3-6’ circle, pulling up as many roots as possible along the way. Pulling ivy this far from the base of the tree will help stop it from climbing back up the trunk, and when new sprouts appear they’ll be easy to spot.

Dispose of the ivy carefully – it’s not advisable to compost it as ivy re-sprouts easily. In fact, there are ways to prevent ivy from re-sprouting: chip or chop it, dry it out on a rock surface, or close it in a bag for several weeks. If you think you’ll outsmart the ivy by tossing the pieces back into the woods, think again – those cut pieces can re-sprout and continue to advance.

Chemicals can be applied; you can “paint” the cut side of the vine that’s still in the ground with glyphosate (brand names such as Round-up, Touchdown, Rodeo, etc.) If this is done immediately after the vine is cut and temperatures are in the 50s, the part of vine still in the ground may be killed, especially helpful if the vine is very mature, large, and tough to pull up out of the ground.

Check out other groundcovers that will serve the same purposes as ivy. Examples include wild ginger, mayapple, partridge-berry, foamflower, creeping phlox, wintergreen, Allegheny (native) pachysandra, bearberry, or Christmas fern. Virginia creeper, a native vine, is a consideration for natural areas but it can be too vigorous for smaller gardens.

Although a fast-growing, evergreen groundcover, over time English ivy usually shows its “dark side,” and as a vine on Alabama’s invasive plant list, should be avoided as an option for our gardens.

For more information about this topic or other horticulture related questions, please contact Sallie Lee, Urban Regional Extension Agent at the St. Clair County Extension office by calling (205) 338-9416 or email leesall@aces.edu.