Does the Phlox Flower All Summer?

Creeping Phlox

• Creeping phlox blooms for approximately six weeks late in the spring and into the early part of the summer in all zones where it grows. It grows close to the ground, and very gradually crawls and spreads. For large areas, propagate the plant by transplanting portions to the area where you wish to grow the phlox; it moves slowly enough that it can take years to fill in a large space.

Tall Phlox

• Growing anywhere from 10 inches to 4 feet high, tall phlox is a summer bloomer. While a few varieties can bloom into September, most tall phlox blooms in July and August. Notable exceptions are the Astoria and Intensia phlox, which bloom beautifully into late fall and even through winter in very mild climates. Astoria grows to about 24 inches, and Intensia tops out around 14 inches tall.

Problems

• Phlox is plagued by a few problems that can inhibit blooming, like spider mites, powdery mildew and various leaf and stem blights. All of these may prevent your flowers from blooming, even if they do not kill the plant. Cutting the plants back in the spring before new growth appears may help, depending on the problem. Otherwise, watch out for early indications like leaf spots and plants that appear sickly, and apply the appropriate pesticide or fungicide for the problem.

Encouraging Bloom

• Treat any problems found with your phlox immediately to protect your plant's blooming season. Commercial pesticides and fungicides can be sprayed or dusted on the phlox. Phlox enjoy having constantly moist roots but dry foliage. Feeding, either with a good compost or a commercial fertilizer, is also important to their success. Whatever color you choose, care must be taken to dead head the phlox (that is, to pinch off the expired blossoms) to keep the seedlings from reverting to pale magenta.