My older (1938) home lot is small by current suburban standards. The island between the front sidewalk and the street is about six feet wide, and has a good bit of natural pitch that slopes upward and away from the street. Growing in this island is an Ash tree with a 52" girth, which I like and want to keep as healthy as possible. Over the eight years I've lived here, the root structure at the base of the tree has pushed up from the surface of the lawn in considerable measure. To the sidewalk side of the tree, I've had to replace sidewalk tiles because of the heaving - no big deal there. But on the part of the island between the trunk of the tree and the street, which I used to be able to push a lawnmower over with no diffuculty, the area has become a woody half-dome with a virtually vertical wall that begins where the curb stops. Around this area there is a small but steady amount of soil erosion I would like to control. I tried to re-establish grass on this domed area by applying topsoil, grass seeds and burlap over the problem spot, but the soil didn't stay put and the grass never got re-established. I would appreciate any advice as to ground cover or any other suggestions for dealing with this issue, so long as they don't involve removing the tree. Thanks!

Steve

 

White and green ashes have a spread of 40-50' and 50-80' in height at maturity. As tree continues to grow, you may see the curb pushed out and broken and the street heave. You can consult with an arborist about the health of your tree, possible root pruning, and barriers that may keep tree from causing sidewalk, curb, and street damage. In the interim you can cover roots with soil and landscaping mesh to check erosion and mulch. Getting anything to grow under a tree can be challenging due to competition for light and moisture. Spring flowering bulbs and pansies may due well in spring when soil tends to be moist. Annuals usually succumb to heat and drought because the tree demands the moisture and not enough light due to shade.

Some ground covers prefer moist conditions and others dry. Those that prefer dry tend to prefer sun. Some are invasive and some are climbers, neither of which you need in a contained area. It may take some experimentation to find one that may adapt to the site conditions.

Lily turf (Liriope muscari, L. spicata) and Mondo grass (Ophiopagon japonicus) tolerate dense shade, are low-maintenance and quite drought tolerant once established. Other ground covers that tolerate some shade and drought include Day lilies (Hemerocallis spp), Small Confederate jasmine (Trachelospermum asiaticum), Star jasmine (T. jasminoides), Coontie Zamia pumila), and Wedelia (Wedelia trilobata). Day lilies and Wedelia have flowers.

Don't over plant because most will spread and fill in. Consider size of plants at maturity. Like the ash tree, the planter did not consider its size at maturity, failure to consider size and growing habits can cause work and worry in the future. It takes about two years to establish ground covers. Keep mulched to conserve moisture.

Whatever plants you choose for your landscape, knowing everything about them before purchasing is recommended. Site conditions, size at maturity, growth characteristics, and maintenance are important.