A common question I always seem to get is “What is ground cover?”
Simply put, anything that covers the ground. This could include lawn, artificial grass, decorative rock and plants.
I know when people ask, they’re talking about plants. My definition of a ground cover is simple – a plant that grows wider than it is tall. Or a plant that may have a spreading habit, meaning the plant roots itself into the soil as it spreads.
The lawn is a ground cover; in fact, it is a specialized ground cover. Lawn is a type of ground cover that can take the abuse of people walking and playing on the lawn. Lawn also has advantages, as it is soft to play on, whereas a ground cover like junipers would be terrible to try and picnic on. Ground covers that abuse people walking, running, lying and playing on them are often called lawn substitutes.
Many people identify a lawn as different from a ground cover because it needs to be mowed. A ground cover may need to be mowed or mowed on a one-, two-, or three-year basis, depending on the type of plant.
A ground cover may or may not be water efficient. A drought-resistant ground cover can save you up to 90% of the water you would normally use to water your lawn. Some ground covers may require more water than your lawn. I have seen people remove their lawn and replace the lawn with a ground cover that requires more water than grass. Remember that lawns have a purpose; they are for playing, running and lying down. On some highways and hills, they plant grass, but they don’t mow the grass. The grass can reach two feet high. In these cases, the grass can be very drought resistant.
I identify two categories of ground covers. The first type spreads on the ground and forms new roots. These ground covers can spread indefinitely. Spreading ground covers either have an aggressive root system to help spread the plant or a fast growing stem and root easily. They are best used as underbrush for tall shrubs. These ground covers are generally the best type for slopes or erosion control. Spreading ground cover requires more frequent mowing or shearing. Some broadcast ground covers include:
Wild Strawberry, fragaria chiloensis – Requires as much or more water than most low growing lawns, requires iron fertilizer.
Spring Cinquefoil, potentilla verna – Requires more water than most lawns, low growing, requires iron fertilizer. Dwarf looking strawberry.
Aaron’s beard, hypericum calycinum – Can grow to three feet, needs shearing annually, requires iron fertilizer, large yellow flowers through summer. This plant is drought tolerant.
Cotton lavender, santolina chamaecyparsisus – Very drought tolerant gray foliage with yellow flowers, shearing about every two years.
Iceplant, several species – Will freeze to the ground most winters but will regrow from the roots. During very cold winters, the plants will freeze completely. Very colorful flowers should be sheared annually. Iceplant is a good drought tolerant plant. Tends to require replanting every five to 10 years due to crown rot in original plant locations.
Star Jasmine, trachelospermum jasminiodes – Woody stems with dark green leaves and white flowers. Should be mowed every three years. Star Jasmine is drought tolerant.
Treasure flower or gazania — Gazania spp. Hanging or bushy habit, with many different flower colors. It is best to replace after three to five years, as the crown of the original plant rots.
Vinca spp., periwinkle — Blue or white flowers on green or white and green leaves. Must be sheared annually. Periwinkle is slightly drought tolerant. Requires shade in Antelope Valley. Not to be confused with the Madagascar oerwinkle, which is a summer annual flower.
To name a few: Ajuga, bergenia, snow in summer, creeper in winter, ivy and lippa. Herbaceous spreading ground covers that can freeze to the ground during the winter include yarrow, asparagus fern, dusty millefolium, shasta daisy, coreopsis, California poppy, alyssum, and candytuff.
The other type of ground cover is woody shrubs. These are plants that are wide-growing, which means that the plants grow wider than they grow tall. They can cover a large area, but usually do not root in the ground. Examples of these ground cover types include junipers, Indian hawthorn, cistus, and coyote.
As with any plant selection, you must decide on the height of the plant. Do you want flowers? What flower color? What is the size of the leaves and what color of leaves. How much exposure to sun, wind, heat and cold will the ground cover receive? How much maintenance does the ground cover need to look good?