Phlox are a colorful and fragrant addition to any garden. Whether low-growing creeping phlox suitable for rock gardens or tall-growing varieties, they will quickly become a favorite. In hot, humid areas, tall phlox are susceptible to fungus, but resistant varieties are available. Phlox grow quickly, multiply well, make lovely cut flowers, and attract hummingbirds and butterflies.
Where to Plant
Choose well-drained soil. After a hard rain, if you still have puddles of water in 5 hours, phlox won’t do well. They want moist but not wet soil. Different varieties prefer full sun to partial shade. In zones 8-9, plant phlox in full shade. Allow plenty of air circulation around plants to avoid fungal infections or mildew.
Best Planting Methods
Prepare the soil well by digging down at least 12″ and mixing in compost until you have a nice crumbly mixture. If transplanting seedlings, dig a hole about twice the diameter of the plant. Keep phlox 1 to 2 feet apart, depending on the variety. Settle the roots into the soil, spreading them out gently and covering them quickly. The top of the root ball should be level with the surface. Tamp soil gently and water generously. If planting bare roots, prepare soil as above. Place the roots into the soil with roots pointing downward and spread out. Be sure the growing point is at surface level. Tamp soil gently and water. New growth will begin to appear in 2 to 3 weeks.
Care of Mature Plants
In spring, apply a thin layer of compost and about 2″ of mulch. This will help retain moisture in the soil and keep weeds to a minimum. Water deeply once per week if you get less than an inch of rain. Remove faded blooms to encourage re-flowering. Divide tall phlox about every 2 to 3 years and replant or give divisions to other gardening friends. Also cut back tall phlox after the first killing frost to about 2″ above the soil.