Skip to main content

Garden Phlox: A perennial favorite!

Garden phlox (Phlox paniculata).
Photo: Mary H. Meyer, UMN Extension
Is Phlox paniculata or garden phlox a favorite in your garden? It is in mine! This tough native (from New York south to Georgia and west to Iowa and Missouri) is dependable, long-lived, offers nectar for pollinators, and needs little care.

Phlox is a Greek word meaning "flame" in reference to the intense flower colors of some kinds. Paniculata refers to the flowers, which grow in a large panicle.

Plant care

As easy as this plant is to grow in full sun and well-drained soils, gardeners need to watch out, because it can readily self-seed and the lovely seedlings that pop up are usually a bright magenta color that may not be at all what you planted or want in the garden.

If you are not careful, these plants may crowd out the white, pink or other colors you originally planted. Named cultivars are usually more attractive and well behaved (sterile or much more so) than the aggressive magenta colored seedlings.

In older, often abandoned gardens, a mass of magenta phlox can be seen naturalized along wooded areas or in a perennial border. The original cultivar may be no longer visible or even alive.

Mildew is a challenge!

Clumps of 'David' in my garden.
Photo: Mary H. Meyer, UMN Extension 
Besides seedlings, the biggest cultural challenge with garden phlox is powdery mildew, which can turn the foliage white and weakens, but rarely kills the plants.

Look for mildew resistant cultivars such as:

  • ‘David’, 3-4 foot tall white flowers;
  • ‘Bright Eyes’ pink flowers 3 feet tall; 
  • ‘Sir John Falstaff', 30 inch salmon-pink flowers. 
Placing garden phlox in full sun with good air circulation and avoiding wet foliage can reduce powdery mildew.

I have a 20-yr old clump of ‘David’ and this year with all the rain, the plants are shorter with much more mildew. I have pruned out sections that have the worst mildew and will remove all the foliage before winter in hopes of reducing the fungus for next year.

I have never divided this clump and for many years I saw no seedlings, but since I left a few seedlings to flower, beware!!!! Now I am removing seedlings on a regular basis, but I have a beautiful soft pink seedling that I kept and a few magenta flowering plants where an ash tree fell down last year. But I remove the other seedlings…..before they take over the whole garden! 

Beneficial for wildlife and insects

Garden phlox is known for the fragrant tubular flowers bloom from July through September. As cut flowers their fragrance can fill a room, and the dense flowers provide good nectar for hummingbirds and butterflies.

If you don’t have phlox in your garden, you should. It is easy to grow and provides a long season of color and enjoyment.

For more information see: Tall Garden Phlox

Author: Mary H. Meyer, Extension Horticulturist and Professor
Print Friendly and PDF