How to Deadhead Phlox

Phlox is a perennial plant that comes in dwarf varieties suitable for borders, and also in three-foot tall, used for background plantings. With proper care, phlox will bloom for six weeks or more during the spring and summer. Deadheading removes the spent blooms and prevents the phlox from setting seed. This prolongs flowering and keeps the plants attractive.

You need

• Small Shears 

1. Use the shears to remove spent flower clusters. As soon as the flowers begin to droop and wilt, go ahead and remove them. As the flowers die, they turn brown and become unattractive. Failing to deadhead also causes the phlox to revert to a pale magenta color, regardless of what you purchased. This is caused by the seed production in the spent blossoms. Cut about a 3/4 inch above the bud forming beneath the spent cluster.


2. Trim the entire flower spike once the clusters have all blossomed and there are not any more buds forming along the stem. Trim right where the spike comes off the plant. Encourage fuller growth by pinching the top half-inch of each flower spike when it reaches six-inches in the spring.  Prune the plants so that each has only five to six spikes. This encourages the phlox to grow full and helps spikes to remain about the same height.


3. Dispose of the spent clusters. Phlox is prone to a powdery mildew with fungal spores that thrive in dead plant matter. The spores then infect the entire plant, killing it. It’s important not to leave the cuttings in the garden, either compost the spent clusters or toss in the garbage.


4. Fertilize the phlox after deadheading. This will encourage a fresh flush of blooms.