Pansy Diseases

Leaf Spots

• Leaf spot diseases, such as anthracnose cause, spotting, browning, blotching and discoloration to pansy leaves. Another leaf spot disease, Cercospora leaf spot, is distinguished from other leaf spot diseases by the purple lesions it causes on leaves. Prevent leaf spot diseases from spreading by picking off infected leaves. Rake up dead debris around the plant. Avoid watering pansy plants from overhead, as suggested by Clemson University. Treat pansies infected with cercospora leaf spot with fungicide.

Rots

• Rots, such as black root rot, root rot and crown rot, commonly infect pansy plants growing in poorly draining soil. Symptoms include yellowing leaves, black roots, wilting, crinkly leaves, stunted growth and sunken areas near the soil line. Prevent rots by planting pansies in areas with adequate soil drainage. Suppress black root rot by applying a fungicide that contains thiophanate-methyl to your pansy, as suggested by Clemson University. Otherwise, remove and destroy pansies infected with rot.

Gray Molds

• Gray mold or botrytis blight is a fungal disease that causes gray, fuzzy growth on flowers and stems, according to Clemson University. Upon close examination, you may notice infected areas decaying or producing a slimy material. Avoiding overcrowding pansy plants prevents infection. Apply a fungicide that contains chlorothalonil or mancozeb every seven to 14 days to treat severe gray mold infections, as recommended by Clemson University. Use the fungicides according to their directions.

Other Diseases

• Other pansy diseases consist of rust, seed smut, downy mildew and powdery mildew, according to North Carolina State University. If you are in doubt about a disease, send a sample to the local cooperative extension office for diagnosis. Prevent infecting your entire pansy flowerbed when buying new flowers. Inspect plants for signs of disease such as discolored leaves, fungal growth or dead areas. Avoid buying any pansies that look unhealthy or diseased.