Why do we plant ground covers? Usually, it is because ground covers will tolerate growing conditions such as shade, poor soils, shallow soils, or near surface-rooted trees such as maples, where grass will simply not grow. Under difficult conditions, we call upon those utilitarian plants that not only tolerate such conditions, but actually flourish under them.
Ground cover plants are specialist plants, serving in landscape design rather like a place-kicker does in a football game, only being called upon under very specific circumstances. Ground covers have been underused for a long time, even though they deserve to be showcased either in a supporting role or as a focal point. They pair well with both evergreen and deciduous plants, helping to create multilevel plantings.
Lambs Ears
There are many varieties of ground covers. They can be evergreen, deciduous, colorful, fragrant, and some are hardy to zone 2. Most ground covers are pest- and disease-free, requiring little to no maintenance. Ground covers have a few disadvantages: Some, like ivy, can take a while to get established, while some others, like euonymus coloratus and houttuynia can be invasive. Even so, the advantage of plants that perform with little care is obvious.
Ground covers include the juniper family, namely the varieties blue rug, shore juniper, and my favorite, Japanese garden juniper. There is no design so easy and yet so gratifying as an island bed featuring jagged boulders with Japanese garden junipers planted among and around them. Ground covers also work well in large containers.
Japanese Garden Juniper
Erosion control is rarely one of the first uses people think of for ground covers, but they are perfect for such a role as they are shallow-rooted and fast-growing when established. Clay soils should be emended with leaf mold (not peat moss, as peat moss tends to move in the soil profile and creates layers which water penetrates poorly). A plant that deserves to be planted more frequently, especially on hillsides, is the kinnikinnick or bear berry, so called because it is one of the main sources of food for grizzly and black bears in the fall. Its foliage turns a fire-engine red in the fall, and makes a lovely contrast when planted with aspen or birch.
Kinnikinnick
Perhaps the best reason to consider using ground covers is simple economics. American households spend billions of dollars on mulch each year. While a freshly-mulched landscape bed looks great, the look doesn’t last. The color begins to fade, usually developing a grayish tone, and then fungus starts to appear. In addition, mulch is wood, and so has a high cellulose content, and cellulose is waterproof, so the mulch sheds water. In the process of decomposing, mulch pulls nitrogen and other elements from the soil, which can cause plants to become chlorotic. Fertilizer must then be applied to replace the elements that the mulch has leached out. Ground covers look quite different than mulch, yet can serve much the same purpose. They may take some time to get established, but will not have to be replaced each year.
Here is a short list of possible choices:
Arctostaphylos uva-ursi (bearberry)
Aegopodium (bishops weed)
Ajuga (bugleweed)
Asarum (wild ginger)
Bergenia (Siberian tea)
Convallaria majalis (lily of the valley)
Epimedium grandiflorum (bishop’s hat)
Euonymus fortunei var. coloratus (winter creeper)
Fragaria chiloensis (beach strawberry)
Galium odoratum (sweet woodruff)
Hedera (ivy)
Houttuynia cordata (chameleon plant)
Hypericum calycinum (St. John’s wort)
Juniper conferta ‘Blue pacific’ (shore juniper)
Juniper horizontalis wiltonii var. ‘Blue Rug’
Juniper procumbens ‘nana’ (Japanese garden juniper)
Liriope (lilyturf)
Pachysandra terminalis (Japanese spurge)
Stachys byzantina (lambs ears)
Sedum (stonecrop)
Sempervivum (hens and chicks)
Xanthorhiza simplicissima (yellow root)
Have fun, do some research, imagine, and watch your garden grow!