Pests & diseases › Downy Mildew
Downy Mildew
Different organism from powdery mildew. Pale yellow patches on upper leaves, fuzzy gray-purple growth below.
Symptoms
- Pale yellow or pale green angular patches on upper leaf surfaces
- Fuzzy purple-gray fungal growth on undersides
- Patches bounded by leaf veins (angular look)
- Whole plants can collapse in a week
Lifecycle
Thrives in cool wet weather, opposite conditions to powdery mildew.
What to do
- Remove infected leaves quickly
- Copper fungicide as protectant
- Improve airflow
If it's bad
- Mancozeb where still registered
Stop it coming back
- Resistant basil varieties (Prospera, Rutgers Devotion)
- Resistant cucumber/lettuce varieties
- Drip irrigation only — no overhead watering
- Wide spacing
Crops it goes for
Plan the plot, track every sowing, cook the harvest
Sowing reminders and harvest forecasts for your own frost dates, the Seed Tin, Scan Centre for any label or packet, and the Potty Mouth Garden Club. Free to start.