Addressing Fungal Spots and Insect Damage on Pansies

Diagnosing the Problems

Your pansies show two distinct issues:

1. Black leaf spots: Likely a fungal leaf spot (e.g., Alternaria, Cercospora). Common in cool, wet conditions or when plants are stressed by heat.
2. "Dried milk" marks: Probably honeydew residue from aphids or whiteflies, or possibly powdery mildew (white, powdery patches).

Immediate Actions

• Remove severely affected leaves to reduce inoculum.
• Improve air circulation by spacing plants adequately.
• Water at soil level, avoiding wetting foliage.

Treatment Options

For Fungal Leaf Spots

• Apply chlorothalonil (Daconil) or copper fungicide according to label.
• Organic option: Cornell formula (1 tbsp baking soda + 1 tbsp horticultural oil per gallon water) sprayed every 3–5 days.

For Insects (Aphids/Whiteflies)

• Systemic soil drench with imidacloprid (Bayer Advanced) for season-long control.
• Foliar sprays: insecticidal soap, neem oil, or pyrethrin-based products.

Seasonal Reality Check

Pansies are cool-season annuals. In hot weather, they naturally decline. If temperatures are consistently above 75°F (24°C), consider replacing them with heat-tolerant summer annuals.