Ground cover refers to low-growing, spreading plants that help prevent erosion, weeds, and water loss.
Bare dirt in the garden is not a good thing. Naked soil is vulnerable to wind and water erosion, compaction, and nutrient leaching. The Dust Bowl of the 1930’s is a perfect example of what happens when soil is not managed properly. Topsoil is a precious commodity and we all need to work to protect it. Ground cover is an excellent method that requires very little effort and improves biodiversity in the garden.
Benefits of planting ground cover
As the roots of ground cover plants work their way deeper into the soil, they help prevent erosion and the loss of nutrient rich topsoil and water. The leaves and stems shade the ground, stabilizing temperatures. Ground cover plants also reduce the chance that weeds will grow. In fact, ground cover plants are used to replace weeds.
Ground cover plant selection
Ground covers are traditionally shorter plants, but they come in a variety of heights, colors, and textures. There are five basic types of ground cover:
A good resource for plants suited to the Bay Area can be seen at the UCANR pages on ground cover. Wikipedia also provides links to many popular ground cover plants. Keep in mind, when selecting ground cover, that many of these plants will spread and fill an area. Invasive plants, such as Algerian or English ivy, ice plant, periwinkle (Vinca major) and licorice plant should not be used. In theory, traditional sod lawns are a form of ground cover, but they are unsuitable for drought-prone areas, requiring unsustainable amounts of water and nutrients.
Yarrow (pictured) makes an excellent ground cover. It can grow as tall as 2’, but will maintain a low growth if it is mowed occasionally while still young. It grows well in our hard clay soil and its soft feathery texture feels wonderful on your feet! Oregano and other low-growing herbs smell wonderful as you walk on them, and curly endive is surprisingly durable. If you don’t mind some height, annual rye grass has been shown to put roots down as far as 40”, helping to break up compacted soil. Mustard can help, too.
Ground cover vs. cover crop
Cover crops are usually grown with the intention of pulling them out of the ground and leaving them on top to decompose, or digging them into the soil, to return all of the nutrients contained in the plants back to the soil. Ground covers are plants grown with the intention of leaving them to continue growing indefinitely.
Plant-less ground covers?
Rather than exposing valuable topsoil to the elements, mulch is another option to ground cover plantings. Wood chips can be found for free from local tree trimming companies and it makes an excellent protective barrier. As the mulch breaks down, nutrients are added to the soil. Also, the mulch helps retain moisture and stabilize temperatures, providing a safe haven for earthworms and microorganisms that improve soil health.
You can grow a surprising amount of food in your own yard. Ask me how!