What is a Creeping Phlox?

Creeping phlox is an herbaceous groundcover native to the Eastern United States. It famously produces a riot of spring color in bright, tightly-clustered bursts of flowers, and is commonly used as a groundcover or border. Creeping phlox is especially well-suited to rock gardens, butterfly gardens, and low-water gardens, and it is available in many garden stores. Numerous cultivars are often available, and staff may be able to special order a desired color for customers.

This plant is evergreen, retaining needle-like leaves year-round. It thrives in USDA zones three through nine, producing white, red, pink, blue, purple, and variegated flowers, depending on the cultivar, in the spring months. Typically the entire plant is blanketed in flowers in the spring, and most gardeners pinch back or prune the plant after flowering to encourage it to develop dense, vigorous foliage.

Creeping phlox propagates itself through horizontal budding stems, explaining the “creeping” name, as the plant creeps along the ground in addition to growing upwards to around knee-height. It can grow extremely rapidly in the right conditions, preferring full to part sun, loamy, well-drained soil, and light watering. You may also hear creeping phlox called “moss pink,” or Phlox subulata, among the Latin-inclined.

This plant can take advantage of limited soil and dry growing conditions, which is why it is so popular in rock gardens and low water gardens. The horizontal stems also root readily, making creeping phlox an appealing plant for use in erosion control on hillsides and river banks. It also attracts butterflies and other beneficial insects, especially during the spring blooming season.

The rich color of creeping phlox in spring can be quite appealing, and many people find this plant desirable for that reason. It can also be used as an herbaceous border for flower beds and paths, although it may require frequent pruning to stay within desired boundaries.

Although creeping phlox can be quite attractive, it can become a nuisance. The plant spreads rapidly and takes root essentially anywhere it comes into contact with soil, which means that it can quickly establish itself, becoming difficult to eradicate. It tends to choke out native species by growing them out of the soil, and grows so quickly that many native species cannot keep up with it. This is something to consider when thinking about using creeping phlox in the garden if you do not live in the Eastern United States. You may be able to find a native species which serves the same function without disrupting the natural environment. Local native plant societies and garden stores usually have information about native alternatives to popular exotics.