Groundwork for June 30, 2013

This Thursday is Independence Day. Free yourself from weekly mowing by replacing part or all of your labor-intensive lawn with a low-maintenance ground cover.

By reducing the size of your lawn by converting it to an alternative ground cover, you can “beat the heat” and have extra time on your hands.

Areas planted with ground covers establish landscape effects that are impossible to create with grass — and generally require far less maintenance. They provide variations in height, texture and color that enrich their surroundings.

The term ground cover is applied to low-growing plants, other than turfgrass, used to cover areas of the landscape. Perennial, evergreen plants having a sprawling or spreading habit are most often used. The plants used for ground covers are generally less than 12 inches in height.

Because they don’t have to be mowed, ground covers reduce landscape maintenance. They also are useful in areas where mowing would be difficult like under low-branched trees and shrubs, where the roots of large trees protrude and in confined areas. They are also the best solution to areas under trees that have become too shady for grass to grow.

When making your selection, carefully consider the characteristics you would like the ground cover to have as well as the growing conditions where it will be planted. Also look at the size of the area to be planted.

Only the most reliable, fast-spreading and reasonably priced ground covers should be considered for large areas.

Monkey grass (Ophiopogon japonicus), creeping lily turf (Liriope spicata) and Japanese ardisia (Ardisia japonica) are good choices for shade to part shade. Asiatic jasmine (Trachelospermum asiaticum) and liriope (Liriope muscari) are excellent for part shade to sun.

Whatever type of ground cover you choose, proper preparation of the planting area will help ensure good establishment and faster growth.

First, remove all existing unwanted vegetation such as lawn grass or weeds from the area physically or with a herbicide such as glyphosate. Next till the soil to loosen it. If you are working under a tree, use a turning fork to minimize damage to the tree’s roots, and avoid severing roots larger than an inch in diameter whenever possible.

After the soil is broken up, spread 2 inches of organic matter (compost, peat moss or rotted manure) over the surface and work it in. If necessary, 2 or 3 inches of additional blended soil mix (generally called topsoil or garden soil) may be added at this point.

Finally, sprinkle a general-purpose fertilizer over the area and thoroughly blend everything together. Plant the ground cover at the proper spacing. This varies with the type you chose, so check with the staff at the nursery or your local LSU AgCenter office.

Planting at the closest recommended spacing will provide quicker coverage, but it will cost more money. Generally, decide on a budget for the project, purchase as many plants as you can with the money and evenly space them in the area to be planted. If you need more plants, purchase them as more funds become available, and plant them evenly among the existing plants.

After the area is planted, be sure to mulch it with an inch or two of your favorite mulch, such as leaves, pine bark, pine straw or shredded pine straw, and water the area thoroughly.

Until the ground cover fills in (which may take several years), weed control is very important. Your best defense is a good layer of mulch. Hand-weed regularly as necessary to maintain good weed control. In addition, most ground covers spread faster when mulched.

Q&A

What is the best way to get grass to grow under a live oak tree? I’ve had the lower limbs removed but it didn’t help.

Lack of direct sunlight is the basic reason why lawngrass will not grow under a mature shade tree. Contributing factors include soil pH, soil fertility, compacted soil, low mowing height and insufficient irrigation. Improve growing conditions around the periphery of the tree to encourage grass growth. It will become increasingly thin as it ventures into heavier shade and finally stop altogether. Consider mulching under the tree, allow tree leaves to accumulate over time or plant a shade-loving ground cover or landscape plants.

I’ve had several shrubs die suddenly in my yard in a matter of just a few days and I’m afraid whatever is causing this will spread to the rest of my plants. What can I do to prevent this from happening?

I am receiving numerous calls about shrubs and small trees suddenly dying. The record-breaking rainfall last December through February saturated the soil and prevented oxygen from reaching plant roots. Injured plants are unable to pick up water from the soil and transport it to the leaves, resulting in dead leaves and branches, maybe the entire plant. Soil-borne root rot diseases likely worsened the situation and with summer temperatures increasing the plant’s need for water there simply are not enough roots left to do the job.

I had healthy tomato plants full of fruit suddenly die in my garden. I’ve had a garden in this spot for more than 10 years and this is the first time this has ever happened. Can you help?

Bacterial wilt affects several plant species, including tomatoes, eggplants and peppers. The disease is characterized by sudden plant wilting without leaf yellowing, often overnight or within two to four days. The disease is soil borne and persists for many years.

Positively identify this disease by suspending a clean section of diseased stem cut from the bottom of a wilted plant in water. A white, milky stream of bacterial slime will flow from the cut end into the water within 30 seconds to 5 minutes.

There is no chemical control. If practical, grow tomatoes in a different garden site or in containers. Clean hands and fingernails, tools, stakes and cages, and shoes to prevent cross-contamination of infected soil. Plant more than one variety and try the resistant varieties BHN 669 and Florida 7513.

Got a gardening question? Write to Bob Souvestre, horticulturist with the LSU AgCenter, at Burden Center, 4560 Essen Lane, Baton Rouge, LA 70809, or email to bsouvestre@agcenter.lsu.edu, or call Master Gardeners at (225) 763-3990.