How would you like a perennial that is hardy from USDA zones 3 through 9, tolerates browsing deer, drought, and smog, while attracting butterflies with its brilliant flowers? Moss phlox (Phlox subulata, also known as moss pinks and creeping phlox, does all that, and more. A very low growing groundcover that barely reaches six inches in height, moss phlox spreads to a diameter of two feet, making it ideal for the front of a border. The leaves resemble short, prickly pine needles, and are a gray-green in color. But it’s the flowers that cause me to run to the garden center for more.
The simple, five-petaled blooms hug the plant in mid-spring, completely obscuring the foliage. Colors range from white through pale pink to a vibrant magenta, as well as lavender and—my favorite—a candy-striped combination. Blooming in mid-spring, the brighter hues provide a dramatic complement to other intensely-colored blooms, such as Dianthus, Salvia, or one of the low-growing speedwells (Veronica). Or tone down the heat by planting them next to similarly-proportioned ground covers with gray foliage—I love how mine look next to a patch of snow-in-summer. On the other hand, the unassuming character of the more delicate shades helps them blend into naturalized areas.
Moss phlox is also an excellent choice for rock gardens or spilling over a rock retaining wall. Or try an expanse on slopes too steep to mow.
Native to the eastern and Midwestern US and Canada, moss phlox needs more rainfall than we get here in Colorado. For best results, irrigate regularly to moisten the soil, but plants will tolerate temporary drought. Make sure the roots have excellent drainage; they do particularly well in sandy or gravelly soil, which is just what I have in my yard.
Phlox blooms best in full sun, and are a good choice for that sun-baked spot that intimidates other perennials. Shear off spent flowers to encourage a sparser re-bloom, or let them go to seed. If conditions are right, you’ll get volunteers next spring. The perennial plants are hardy to USDA zone 3, making them well-suited to higher elevations, and may stay green all winter if temperatures don’t get too cold.
While the closely-related tall garden phlox is often plagued by powdery mildew, moss phlox is rarely bothered. If the plants are continually hot and dry, you may see spider mites—washing the foliage regularly can help. My worst problem is rabbits. I couldn’t figure out why my plants weren’t blooming; then I saw that the flowers were being nibbled off by bunnies. Grrr! (A regular regime of spraying with nasty-smelling rabbit repellant solved that problem.)
Moss phlox is widely available to garden centers and big box stores. I think I’ll go pick up a few more today!