Four Ground Covers
This abridged article appeared in the June 1997 Azalea Chapter newsletter
After the genus Rhododendron, many of my favorite plants are those that propagate themselves freely, and some of the best at that are ground covers. One of the rewards of gardening is seeing the plant that you bought in a 4-inch pot spread out year after year to cover a space several feet across. Another is giving starts of your plant to friends (or contributing them to our plant sales). I have chosen four ground covers that have a lot in common. They stay less that 6 inches tall, forming thick mats that few weeds can penetrate. They spread at similar rates, advancing 8 to 12 inches a year. And they are shade-tolerant, growing well where rhododendrons and azaleas thrive. In bloom they cover the spectrum. Campanula poscharskyana is blue, Silene polypetala pink, Chrysogonum virginianum yellow, and Phlox stolonifera purple, pink, blue or white.
Do not dismiss Campanula poscharskyana (Serbian bellflower) because you have had bad luck with other Campanula species. I have tried three or four and this is the only one that does well in my garden. The blooms cover the foliage and sprawl out well beyond it in April. They look especially good spilling over a wall. The bloom stems don't need to grow vertically, like some of the other campanulas, and therefore they don't stretch up and fall over in a shady location. I don't know if I have ever seen this plant in a local nursery; I got mine at the Atlanta Botanical Garden plant sale years ago.
Silene polypetala is another one that I have not seen often in the nurseries, probably because it doesn't look like much in a pot, but it is worth finding. Like the Chrysogonum and the Phlox, Silene polypetala or fringed campion is a Georgia native, but Silene polypetala is on the endangered list. It forms the thickest mat of the four and the mossy color and texture contribute greatly to the garden when it is not in bloom. The blooms, which show up in late spring, are a pale pink, about the size of the quarter and very deeply cut.
Phlox stolonifera is the least dense of the four and loses the most leaves in the winter. Consequently it requires a little weeding. It is irrepressible, however, and now it is finding its way out of the bed where I planted it and into the pathway, one sign that my garden is finally becoming mature. As I was weeding this spring, I discovered something special about one of my phlox, 'Sherwood Purple', I think. I have been growing this plant for six years and have always seen the color as a pure purple, but when I looked very closely, I discovered that the blooms are a blue background with red stripes radiating irregularly out from the center. The garden is a great place for such surprises.
Chrysogonum virginianum is a newcomer in my garden, but it is doing well in a location where it has to contend with roots from a nearby hackberry tree. A 4-inch pot is now an 18-inch mat. It begins opening its dandelion yellow blooms in March.