Ground Covers For Energy Conservation
by Dr. Robert Black, Consumer Horticultural Specialist

Many herbaceous and woody plants can be used as ground covers to save energy and reduce maintenance. Horticulturists are not always in complete agreement as to the exact definition of a ground cover. As used here, the term "ground cover", refers to any low growing plant that can be used to cover areas where turf is not desired or will not grow. Ground covers can help reduce energy use in the landscape by substituting for energy intensive grasses and by providing a cooler microclimate.

Much time and energy is spent maintaining top quality turf areas, which must be frequently mowed, fertilized, watered, and sprayed. Turfgrasses are difficult and/or dangerous to mow on slopes, near traffic, and in out of the way corners. They also grow poorly in dense shade and in extremely wet or dry areas. Many ground covers are more adaptable to these problem areas than turf. However, use of outdoor living space should be considered before replacing turfgrasses with ground covers. Turfgrass is still the best choice for recreational areas or areas with heavy foot traffic.

In addition to saving time and energy, ground covers can provide a more beautiful and comfortable environment. Ground covers create interesting contrasts in texture and color and are often the unifying element in a total planting. Ground covers can moderate the climate around buildings by absorbing and dissipating heat rather than redirecting it to people or buildings. Paved surfaces store and radiate heat even after sundown, keeping the area warmer for a longer period of time and making hot periods hotter. Under sunny conditions, researchers have shown temperatures to be 15-25°F cooler immediately over planted areas than over asphalt or concrete. There is also evidence that taller ground covers can provide even more cooling than mowed grass.

If the proper ground cover is selected for a site, very little maintenance will be required. Plants native to woodlands will out perform grass in heavily shaded areas. There are also appropriate ground covers that will tolerate a wider variety of soil conditions than most turfgrasses. A ground cover such as lippia (Lippia (Phyla) nodiflora) tolerates wet soils much better than most turfgrasses. Watering can also be reduced by using a drought resistant ground cover, such as juniper.

It may take up to 2 years to establish a ground cover area, and during this period weeding, watering, fertilizing and mulching will probably be required. Once established, most ground covers require only an occasional weeding and trimming to maintain them in bounds.

Ground covers used correctly can reduce maintenance cost, save energy, and provide a more pleasant environment. Ground covers also enhance the beauty and usefulness of the landscape.