The Wilting of Garden Phlox

Garden phlox, or Phlox paniculata, is the most commonly grown phlox species, according to Iowa State University Extension. This summer-blooming flower, reaching 2 to 4 feet at maturity, sometimes displays wilted leaves as the result of pests, diseases or poor growing conditions.

Growing Conditions

Garden phlox needs moist but well-drained soil in a location with full sun. Lack of moisture sometimes causes wilting and poor growth, especially during the hot summer months. Water in the morning, avoid wetting the foliage to reduce risk of disease and mulch to help retain moisture, suggests University of Minnesota Extension.

Diseases and Pests

Powdery mildew commonly affects garden phlox. Leaves and foliage develop a white or gray fuzzy fungus, with leaves yellowing and wilting, finally turning brown and dropping off later in the course of the disease. Spider mites also attack garden phlox, with symptoms including wilting and browning of leaves. Spider mites cause more trouble during hot, dry weather and sometimes cover plants with fine webbing.

Prevention/Solution

Keeping garden phlox well-watered and otherwise well-maintained gives them the best possible natural defense against wilting for any reason. Insecticidal soaps work against spider mites, while eradicating powdery mildew requires a fungicidal spray. Prevent future problems with fungus and other diseases by transplanting phlox to provide adequate space between plants with good air circulation. Cut infected parts off in the fall to avoid additional problems the next growing season and avoid overhead watering, suggests North Dakota State University.

References

• University of Minnesota Extension: Tall Garden Phlox for Minnesota Gardens
• Iowa State University Extension: Perennial Phlox for the Home Garden
• North Dakota State University: Questions on Phlox

Resources

• University of Illinois Extension: Garden Phlox
• University of Arkansas: Garden Phlox