How to Care for Phlox Plants

Garden phlox (Phlox paniculata) is a flowering plant that blooms in the summer. Growing to 4 feet in height, phlox is attractive in both borders and beds. According to horticulturists with Iowa State University, most phlox is highly susceptible to powdery mildew; they suggest you look for resistant varieties, such as 'Eva Cullum' and 'David.' Phlox is hardy to U.S. Department of Agriculture Hardiness zones 4a through 8b.

Things You'll Need

• Mulch
• Pruning shears
• Fertilizer
• Fungicide spray

Instructions

1. Water phlox at the soil level, not overhead. Keep the soil moist at all times. Hot, dry weather may require more frequent watering.

2. Spread a 2-inch layer of mulch on the soil around the phlox in the spring. Mulch helps discourage weed growth and keeps the soil cool during the summer.

3. Cut all but five or six stems from the plant when the phlox reaches 6 inches tall. Pinch 1/2 inch off the tip of the remaining stems. This helps encourage the phlox to produce larger flower clusters and improves air circulation within the plant, lessening the chance of the plant contracting powdery mildew.

4. Fertilize the phlox in the spring with an all-purpose fertilizer, applied in the amount suggested by the manufacturer. Apply the fertilizer to the soil and water after application.

5. Look for signs of powdery mildew. The most obvious symptom is a white, powdery substance on the plant's foliage. Horticulturists with the University of Minnesota Extension recommend fungicide spray containing sulphur or chlorothalonil to combat powdery mildew. Apply the spray according to the package instructions.

References

• Iowa State University Extension; Perennial Phlox For The Home Garden; Richard Jauron; 1995
• University of Minnesota Extension; Tall Garden Phlox for Minnesota Gardens; Deborah L. Brown; 2009
• "Perennial Reference Guide"; Karleen Shafer and Nicole Lloyd; 2007