Most groundcovers can be planted at any time of the year. However, fall planting takes advantage of lower temperatures and natural rainfall. Watering is reduced and plants establish a stronger root system before summer. Summer planting requires adequate and frequent watering for survival and establishment.

Space the plants according to their size, the immediate effect desired, and their rate of growth and habit. If the individual plants are spaced too far apart, weeding can be a problem and the time required for complete coverage can be quite long. On the other extreme, planting too closely together can be a needless waste of time, money and plant materials. In addition, there will be increased competition as the plants grow into maturity. Usually, it is best to space the plants so the groundcover areas will, for the most part, be completely covered by the end of the third growing season. A staggered row-planting pattern usually will result in the quickest cover of the planting bed.

CARE

Weed control is a must until the groundcover is fully established. A 2-inch layer of mulch will help in the control of weeds. On slopes, coarse netting is also used to hold the slope until the groundcover is established.

It may take up to two years to establish a groundcover area. Fertilizing and watering will probably be required during this period. Apply fertilizer based on how fast you want full coverage to occur. Begin fertilizing 4 to 6 weeks after planting, then make one application in the spring, another during summer, and a third in September. If rapid coverage is desired, make a fourth application during the summer months. A complete fertilizer such as 12-4-8 or 16-4-8 or a similar analysis applied at the rate of 1 pound of nitrogen per 1000 square feet is adequate. To determine how much fertilizer to apply per bed, measure the area of the bed in square feet (length x width). Then, use this equation:

Area of bed divided by 1,000 square feet, divided by the percent of Nitrogen in the bag, will give you the amount of fertilizer that needs to be applied to the bed. For example, if the bed measures 200 square feet (20 feet long and 10 feet wide), you can determine that 200/1,000 divided by 12 % (or .12) = 1.6. Therefore, 1.6 pounds of 12-4-8 will need to be applied to this 200- square-foot area.

The next consideration is adequate and timely watering. Water requirements vary with different plants. Groundcover plants should not be allowed to wilt.

Some groundcovers are improved by occasional shearing. Wintercreeper can be clipped at a 4- to 6-inch height. Others, such as creeping lily turf, can be clipped with hedge shears when they appear shabby. Remove the old growths of liriope and mondograss because the leaves harbor fungi, which can disfigure and kill newly emerging leaves. To rejuvenate pachysandra and other herbaceous evergreen groundcovers that have suffered winter burn, use a rotary mower on its highest setting. Early spring is usually the best time to prune groundcovers because new growth will quickly cover the bare stubs. Cut out dead branches and remove winter-damaged branch tips to encourage dense new growth.

Avoid severe pruning in late summer or fall since it can force tender growth that will not have time to harden off properly before winter.

Horizontal junipers like Blue Rug, Bar Harbor, and Prince of Wales tend to form new foliage on top of older foliage and become thick and dense once their canopies meet. Thinning improves air circulation between the plants and prevents insect and disease problems.