The ivy among us Dealing with a garden troublemaker January, 2007

Among the plants that flourish in this area is English ivy, long a favorite for back-yard gardeners.

Ivy is an amazing vine/shrub: beautiful year-round; requiring no maintenance to look attractive; resistant to drought; tolerant of dry shade, even deep shade; seemingly the perfect vine to cover old New England college walls, and unattractive chain link fences.

The Ladew Topiary Garden in Monkton, Maryland is a world-famous garden featuring amazing (and very large) topiaries of varied design, built by an American devotee of English fox-hunting and of English gardens.

You have to see it to appreciate what ivy and boxwood, etc. can do for the imagination.

Ivy flourishes in our local parks because it has been planted by generations of homeowners.

But ivy is a thug!

Ivy is one of the most common--and troublesome--plants in local gardens. It is unusual in Takoma Park and the shadier sections of Silver Spring to find a garden of an old house that does NOT have some ivy.

Ivy promoters and opponents agree on one point: it should not be ignored. If you don't keep your eye on it, you won't have a garden, you'll have a jungle.

•   Ivy will strangle your beautiful azaleas.
•   Homeowners dread the annual ritual of pulling and clipping that is necessary to control the invasive vine.
•   Having small rodents and snakes settle in under its rampant leaves is enough to keep many a homeowner out of the ivy permanently.
•   A healthy stand of ivy is very thirsty and will leave the earth and your shrubs/trees parched.
•   Serious gardeners and landscape designers turn up their nose at ivy, dismissing it as an overused weed, or worse.
•    In its Tree Ordinance, Takoma Park has a ban on planting ivy.
•   Park authorities see it as a non-native pest that is smothering wildflowers, native shrubs, and trees.
•   The Maryland-National Capital Park and Planning Commission is so concerned about ivy and other so-called invasive plants that it is recruiting volunteers to pull out the 'aliens' by hand. The effort is called the Weed Warrior program. Call Carole Bergman, the Commission's forest ecologist, at 301-949-2818.

How ivy hurts trees and homes

Ivy's habit of growing up tree trunks has provoked unending debate over possible damage to the tree.

Ivy is not parasitic, but it does add weight to branches and trunks that can make a difference in a windstorm or heavy snowfall.

Ivy leaves obscure the tree's structure and make it more difficult for arborists to evaluate and work on trees.

A heavy mat of tree ivy can hold moisture, promote trunk decay, and harbor non-beneficial insects that bore into the tree to hide from their natural predators.

Similarly, ivy allowed to grow up the side of a wood or brick house is an invitation to trouble. It can adhere so well to a painted surface that it will peel off the paint when removed. Older mortar will be weathered further by the vine's aggressive probing and clasping; new growth can split wood joints apart. [ A trellis spaced a few inches from the exterior or wall is one method of keeping climbing ivy where it can be easily trimmed. ]

Being labeled a thug is a sorry fate for a plant that has been celebrated through the ages. The Greeks wrote poems with ivy imagery. In Victorian England, the vine was used to symbolize friendship or romance. And today, ivy fanciers are busy propagating exotic strains under the banner of the American Ivy Society (www.ivy.org).

Ivy will not leave without a fight

Easy Gardener is often asked how to successfully remove ivy from the garden. The plant is practically indestructible. Running the power mower across the areas of ground-cover ivy will only promote fresh new growth in the Spring.

Many have tried a glysophate product, usually Round-Up. Be aware that the product found on the shelf at your favorite hardware or garden store is a weak solution compared to the commercial. These stores are not licensed to sell the strong variety, because of its toxicity. A Plant Pest Applicator's License is required for its purchase and use.

The tried and true way to remove ivy is to dig deep enough to remove the root system. Merely cutting it close to the ground does not kill the root system.

To remove ivy from trees (this is where it does the most damage) requires first cutting out a six inch section of the stem at about waist height. Removing this much stem/trunk will inhibit the vine's inability to re-grow itself up to its 'mate' above. Enough cutting/removal of the stem around the tree will eventually allow the ivy to die above the cut.

If the tree is truly being suffocated by the vine, you will not be able to remove all the vine which will have imbedded itself in the trunk of the tree up to a treacherous height. A tree company (a quality company whose employees do not use spikes to climb!) will need to do that.

Removing dead ivy from a wall is sometimes not quite so treacherous a climb.

You can try smothering ground ivy with thick, thick, thick newspaper covered with mulch, for six months or longer. But remember that the ivy will grow sideways and can pop up around the edges (much like bamboo).

Once you have removed dead ivy from the ground (or tree) be vigilant that a small piece does not appear to re-invade the area.

So, having done this good deed for the environment, what to plant on that dry, shady slope to stop erosion and be green and be low maintenance?

Ivy alternatives

The most attractive and interesting plant is the evergreen or semi-evergreen Barrenwort or Bishop's Hat, Epimedium. It has beautiful foliage (light green, heart-shaped, on wiry stems) and forms a dense ground cover beneath trees and on slopes. Among its many selections, you might want to try these:

•   Epimedium versicolor ''Sulphureum', with masses of small deep yellow flowers in early Spring, growing 8-12 "
•   Epimedium grandiflorum 'Lilafee', with purple-lilac, star-like flowers, and divided heart-shaped leaves, growing 12-15"
•   Epimedium youngianum 'Niveum', with white flowers. Its emerging leaves are tinted with red and turn a deep shade of crimson in Autumn. It grows 6-8"

Monkey grass (liriope) is a good ivy alternative.

Epimedium are lovely planted among trees. They begin to spread in their second season. While these plants love moisture, Epimedium adapts to dry soil. Always provide shade. Great companion plants are Viola labradorica, Carex 'Bowles Golden' and Helleborus foetidus.

Another truly reliable ground cover for dry shade is Lilyturf or Monkey Grass: Liriope with lush grassy deep green foliage, or a dazzling array of variegation. Liriope muscari 'Big Blue' , with its clumping habit, grows, 12-15". If your slope is steep, try Liriope spicata, the creeping lilyturf. It spreads happily and grows 12-15".

Easy Gardeners' three readers would love to know if you have any success stories of removing ivy. Write c/o Takoma or Silver Spring Voice.

And Happy Spring. It is just around the corner!

Pat Howell is a Takoma Park gardener and landscape designer/contractor. She is available for hand-holding and answering questions through Deephaven Landscapers.

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