Spreading phlox, also known Phlox diffusa, is a beautiful, colorful ground cover.
It is native from the northwestern US and British Columbia to the southwestern US states and as far east as Nebraska. It can tolerate high altitudes and rocky mountain slopes. The needle-like leaves are yellow-green, and blooms can be found in lavender, purple, rose, white, and pink. Each flower has five petals with a tube-shaped corolla that is joined at the base. Spreading phlox grows best in dry hillside areas, rocky slopes, and alpine or sub-alpine terrains. These plants are perfect for hardiness zones 3-9. Their lightly scented star-shaped flowers bloom from April through July. Butterflies and bumblebees are attracted to Phlox diffusa during the blooming period. The leaves remain green year-round.
Spreading phlox is relatively low maintenance, making it particularly appealing to a novice gardener; merely trim back after flowering is finished to have increased blooms the following year.
In considering this plant for landscaping, it is best used in mass planting, rock/alpine gardens, border edging and for ground cover. This plant grows from 2 inches in height extending to sometimes 6 inches when in bloom, and approximately 24 inches in width. Plants should be placed about 20 inches apart when planting for best coverage. The foliage remains low and dense, has an average growth rate, and have an average lifespan of 10 years with proper care. Spreading phlox grow best in full sunlight, with preference being given to dry or average moisture levels in the well-drained soil. It is drought-tolerant and thrives in an urban environment. Being highly tolerant of pollution, it can even be grown in inner-city areas. In colder climates, it's best to cover with about 6 inches of mulch before winter arrives.
Spreading phlox is an excellent choice to give a rocky or uneven area in the garden a lovely, colorful addition.