Ground cover plants are low-growing ornamental plants that spread naturally over the ground in places where it is not practical to grow turf.
Ground covers are usually either perennial or woody plants. Annual plants are seldom included in the category of ground covers.
Properly selected for their site, ground covers become one of our most useful groups of ornamental plants. One of the most effective uses of them is covering banks too steep to grow and maintain turf.
This not only prevents soil erosion but adds beauty to an otherwise unsightly area.
There are many kinds of trees and shrubs that, due to their shallow roots and dense shade, will not permit grass to grow beneath them. It is here that ground covers fulfill a most important use.
We should not overlook the value of ground covers in helping to keep the ground cool for some of our lilies, hardy amaryllis and other bulbs that dislike hot baked soil in summer.
An attractive ground cover for these bulbs would also improve their appearance when in full bloom, especially for those bulbs that bloom without foliage.
Plants covering the ground along the foundation of the house are useful in preventing rain water from splashing mud up against the house.
Not many ground covers can be planted on surfaces to be walked on without showing some injury to the plants.
However, during Queen Elizabeth’s time in England, mother-of-thyme was used in garden path designs so as to give off a pleasant odor when walked on. Other plants that have rather wiry stems and flexible leaves, so that limited walking would not damage them much, would be common periwinkle, English ivy, bearberry, and japanese honeysuckle.
Different Kinds – Different Uses
Some ground covers are planted for their beautiful evergreen foliage. Others are used for their attractive flowers or colorful fruit. Common periwinkle, English ivy, wintercreeper and the low junipers are common examples of those that remain green throughout the winter.
Not all evergreen ground covers do well in winter sun, so some of them must be planted in dense shade or partially shaded areas. However, in northern Mid-America snow may cover them most of the winter. For that reason they may survive better there than in the southern states. Alpine plants growing naturally at high altitudes in the mountains may live through extremely low temperatures when covered with deep snow but would die if planted in a milder climate at lower altitudes without protection.
Examples of ground covers that have outstanding flowers are evergreen candytuft, snow-in-summer, creeping gypsophila, wild sweet william, moss phlox, and violets.
For especially colorful fruit we depend on such plants as bearberry, checkerberry wintergreen, and to some extent the wintercreeper, low junipers and creeping mahonia.
Ground covers are usually propagated by division or clumps and most of them spread naturally by runners or underground stems. Those that grow from definite crowns such as evergreen candytuft, sunrose and the junipers are propagated by planting seed or by cutting and occasionally by layering.
To Grow Them Better
For best results the soil should be properly prepared before planting. Soils that are in poor physical condition should be improved by adding organic matter, such as peat moss or good composted soil. Heavy clay loam soils would also be improved by the addition of some sand. These materials should be worked into the soil to a depth of six or eight inches. Soils that are low in phosphorus should have two to three pounds per 100 square feet of super phosphate added to the soil before spading.
For foliage rich in color and vigorous in growth, ground covers should never be in need of available nitrogen. A complete fertilizer, applied at the recommended rate on the container, would be a minimal requirement. An application of 1/2 inch of good composted soil once a year would likewise improve growing conditions.
Ground covers, like all other plants, respond to liberal watering during periods of drought. The junipers, japanese honeysuckle, and common yarrow would come nearest to surviving drought under neglect. Heavy watering when the plants show signs of needing water would be more beneHcial than light frequent watering.
The only ground cover listed in this article that might become a pest in the yard or garden would be Japanese honeysuckle. A severe cutting back of growth where it is not wanted, during spring and early summer should be effective in keeping it under control.