Creeping phlox (Phlox subulata) is a familiar spring-blooming creeping plant that is frequently seen in rock gardens, growing from crevices in stone walls, or planted as a flowering ground cover. Surely the best feature of creeping phlox is its flower production. The simple blooms are not only pretty, they’re also remarkably plentiful. The flowers are so densely packed that it can be hard to make out the plants’ foliage from a distance. After the bloom is over, the tiny leaves remain green for much of the year.
Creeping phlox is sometimes known as “moss pink” or “moss phlox,” based on its growth habit. It is often listed as an herbaceous perennial, although it is semi-evergreen and is related to the familiar upright garden phlox (P. paniculata). The plants reach, at most, 6 inches in height and can spread out up to 2 feet to form a mat. Creeping phlox also attracts butterflies and is considered a relatively deer-resistant ground cover.
|Botanical Name||Phlox subulata|
|Common Name||Creeping phlox, moss phlox, moss pink, mountain phlox|
|Plant Type||Herbaceous perennial|
|Mature Size||6 inches tall and 2 feet wide|
|Sun Exposure||Full sun|
|Soil Type||Rich, well-drained|
|Soil pH||6.8 to 7.7|
|Flower Color||Pink, red, white, blue, rose, lavender, purple|
|Hardiness Zones||3 to 9|
|Native Area||Eastern and central United States|
How to Grow Creeping Phlox
All in all, creeping phlox is one of the best perennials to grow in sunny areas. It requires minimal care, a medium amount of water, a bit of seasonal pruning, and perhaps an annual feeding. You can let it spread naturally so it covers a larger area (or simply becomes more brilliant) or trim it back during pruning to maintain a neater or smaller form.
As with many ground covers, grass and weeds growing up through the plant can be a major nuisance. It’s best to start managing weeds early in the season, before the phlox blooms or its foliage is at its fullest. Hand-pulling is the most effective method of weed control and also the safest for the plant. Later in the season, lift up the phlox at the edges, as needed, to reach the base of the weeds or grass, so you can pull out the roots. If you neglect the weeding and let grass get out of control, it might be easiest to pull up the phlox, clear the area of grass and weeds, and replant the phlox.
A slope that faces in a southerly direction is ideal since these perennials grow best in full sun.
Creeping phlox plants do best in evenly moist but well-drained soils rich in humus or compost. They will do fairly well in clay soil.
Creeping phlox typically needs weekly watering, especially during the heat of summer. It is generally more drought-tolerant that most other phlox plants.
Temperature and Humidity
This perennial is fairly robust and can tolerate the hot environment created by rocks, gravel, or path surfaces. It does not need high humidity and generally handles dryness better than most other phlox plants.
A feeding in late winter or early spring will promote growth and support a more robust bloom for your creeping phlox. Feed it with a slow-release flower fertilizer.
Propagating Creeping Phlox
To propagate creeping phlox plants, simply divide them in spring, immediately after they are finished blooming. Dig up the entire plant, including the root ball. Cut through the roots to divide the plant roughly in half, then plant each half as desired. Typically, it’s fine to divide a plant every two to three years without significant damage.
Pruning creeping phlox is optional. After the blooming period, you can shear back the foliage to create a neater form. This also has the effect of making the foliage denser, which can enhance the plants’ beauty as a ground cover for the summer months. Alternatively, you can skip the pruning and let the plants grow naturally. They do not need deadheading, although in some situations shearing can result in a second bloom.
Landscape Uses for Creeping Phlox
Since creeping phlox plants stay short and spread easily, they are widely used as ground covers. Although homeowners with flat land can use these plants as ground cover to form plant borders along lawns or walkways, their dazzling spring flower display is most easily appreciated when they are planted on slopes so they can be seen. These colorful, low-growing plants not only help prevent erosion but also blanket the slope with vibrant color in spring.
If your slope has a retaining wall installed at its base, the plants will spill right over the top—a truly wonderful look. This flowering ground cover is also often used in rock gardens, as an edging plant at the front of a flower border or to fill the cracks between the stones of a stepping-stone path.