by Jan Cashman
To us gardeners, the term “ground cover” means a low-growing plant that spreads. Although we seldom call it that, lawn grass is the most commonly planted ground cover. Other types of ground covers besides grass can add color and texture to your planting beds. These ground covers can provide a living mulch for plants that prefer cool roots such as clematis. Spring bulbs grow through ground covers which will then hide the bulbs’ dying foliage after the bulbs are done. Ground covers can be planted on a slope that is too steep to mow. They add more color and interest than mulches would around shrubs and perennial flowers and under trees. (Be aware, though, that some ground covers are too aggressive to plant with perennials and shrubs.)
There are many beautiful and interesting spreading ground covers that do well in sunny, even hot, locations. One of the first ground covers to bloom in the spring in a mass of pink, white, or pale blue flowers is popular creeping phlox. Iberis (candytuft) is another early bloomer whose pure white flowers stand out against any background. Hardy Basket-of Gold Allysum blooms early with cheerful yellow flowers. Soon after these early bloomers, Saponaria (Soapwort), blooms. Soapwort is a favorite of Jerry’s because of its mass of bright pink flowers in late May.
Cerastium tomentosum (Snow in Summer) is one of the best drought tolerant ground covers for sunny, hot locations. It quickly fills in the area where it was planted. The pretty white flowers of Cerastium stand up above the silvery-gray leaves in early summer. Antennaria (Pussy Toes-called that because the flowers look like kittens’ paws) is another ground cover with silver-colored leaves for sunny, dry locations. The leaves of this native form a low, dense mat.
Potentilla is usually thought of as a hardy, drought tolerant shrub. But there is another species of potentilla, Potentilla ‘Nana’, which is a drought-tolerant, easy-to-grow ground cover with yellow flowers. Potentilla ‘Nana’ is one of the few ground covers that continues to bloom all summer. Veronica repens (Creeping Speedwell) is a favorite of our greenhouse staff because it, too, continues to bloom all summer with tiny blue flowers.
If you have grown strawberries, you know that they are a low-growing, spreading plant. There is an ornamental strawberry, Fragaria rosaceae, with bright pink flowers, not white. Fragaria rosaceae does get a few small strawberries, but its most appealing qualities are its ability to spread quickly and bloom most of the summer. Our ornamental strawberries are already in full bloom bordering an herb bed behind the nursery.
One of the best ground covers for hot, dry locations is sedum. Each variety of this succulent plant has a different texture-some have needle-like leaves, others have leaves in the shape of tiny flowerets. Leaf colors of sedum range from yellow to lime green to burgundy-red to variegated. There is even a variety called ‘Tricolor’ that has a green leaf with a white and red edge. A friend of mine has tucked Dragon’s blood, one of the more popular varieties of sedum with dark maroon leaves, in between the rocks of her south-facing, dry-stack stone wall. It flourishes there with little water. Another creative gardener in Belgrade planted different sedums in a large, low pot to create a checkerboard affect. Most sedums stay evergreen all winter, even in our climate.
Probably our best-selling-and favorite-ground cover for sunny locations is creeping thyme. Tiny-leafed thymes grow close to the ground with pink or lavender flowers in the summer. Thyme is one of the few ground covers that will tolerate foot traffic, so plant it between stepping stones where it will fill in quickly. The wonderfully herby fragrance is released when you walk on it.
Low-growing ornamental grasses, such as blue fescue, make good ground covers if planted close together. Blue fescue’s metallic gray-blue leaves contrast nicely with other perennial flowers and grasses. Low-growing bulbs, such as grape hyacinth, provide a ground cover in early spring when nothing else is up and blooming. Then, they disappear until next spring. Spreading junipers, those that never grow taller than 6″ such as Blue Chip, can be used as ground covers in hot, dry sites or on a steep slope. Vines, such as Dropmore Scarlet Honeysuckle, left to crawl with no trellis, will cover the ground.
When planting ground cover plants grown in small pots, space them 12-18″ apart. Unfortunately, ground covers are not less maintenance than grass. They need care, and most of the work needs to be done by hand. Grasses creeping into ground cover areas can be a nuisance. Mulches, preemergent herbicides, or post-emergent grass killers can help, but it is best to keep up with the weeding before the grass gets out of control.
If you have a slope too steep to mow, a shrub or perennial garden you want to fill in, or a stone path with gaps, try planting ground covers. These sun-lovers will thrive and give your garden added color and texture.