Description
Phlox subulata, also known as creeping phlox, is a vigorous, sun-loving perennial plant that grows only 6” high and spreads 24” wide. It is native to the dry, rocky areas and open woodlands of the Appalachian mountains. Plants will tolerate deer, drought and heat, but good drainage is essential, and watch out for rabbits. Flowers open in April-May over of matted, moss-like foliage. Use creeping phlox as a ground cover in sunny areas, along rock walls, as an edging and on slopes.
How to Grow
Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their germination.
Mulches also help retain soil moisture and maintain even soil temperatures. For perennials, an organic mulch of aged bark or shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
Careful watering is essential in getting perennials off to a good start. Water thoroughly at least once a week to help new roots grow down deeply. Soil should be damp at about 1 inch below the soil surface. You can check this by sticking your finger in the soil. Water early in the morning to give all leaves enough time to dry. One inch of rain or watering per week is recommended for most perennial plants. You can check to see if you need to add water by using a rain gauge.
Until plants become established, some protection from extreme winds and direct, hot sunlight may be necessary. Good air movement is also important.
After new growth appears, a light fertilizer may be applied. Keep granular fertilizers away from the plant crown and foliage to avoid burn injury. Use low rates of a slow release fertilizer, as higher rates may encourage root rots.
“Deadhead”, remove spent flower heads to encourage continuous flowering and prevent seed development.
Remove and discard foliage after a hard frost in fall.
In colder regions, apply another layer of mulch (1-2 inches) after the ground freezes in fall. Evergreen boughs (from Christmas trees) provide additional protection. Remove this mulch in the spring.
Divide in spring every three to four years to avoid overcrowding.
Plants may need staking; stake entire plant up to the flowers.
Tips
To control height, delay bloom and increase the number of blooms, pinch plants back by ½ of their height in late spring/early summer.
Many gardeners do not cut back perennial flower seed heads in the fall, but wait until early spring before the new foliage appears. This provides food for wildlife over the winter.
Avoid overhead watering and divide clumps before plants get overly crowded.
Plants are intolerant of dry spells.
Harvest phlox flowers when 1/3-1/2 of the flowers in the panicles are open.