Question From: Sugar Grove, Illinois, United States
Q: My perennial phlox plant has yellowing leaves underneath the plant. I wonder why it is doing this? I just applied a layer of mulch to the bed it is in.
Fungal diseases on the lower leaves of phlox are endemic. To prevent the spread the infected leaves should be removed. Bag them and put them in the trash. Then spray the plants, including the undersides of the leaves with a fungicide. Be sure to remove and destroy all the surface plant material after frost and treat the phlox every 7 to 10 days next spring. Best And Happy Yardening, Nancy