🥒 Zucchini How hard it is to control: ★★☆☆☆ 2/5

Powdery mildew on zucchini

Very common fungal disease of cucurbits. Appears practically every year, especially at the end of summer.

Symptom photos

Powdery mildew — Leaf covered in white, powdery growth next to a healthy leaf — Leaf covered in white, powdery growth next to a healthy leaf Photo: Schlaghecken Josef, licence CC BY-SA 4.0

Symptoms

White powdery coating on leaves
Leaf yellowing and die-back
Limited fruiting

What it does to the crop

Shortening of fruiting period by 2-3 weeks
Reduction in fruit size
Worse zucchini taste

What encourages it

Warm weather with moderate air humidity (50-70%)
Dry leaf surfaces
End of summer

Prevention

Resistant varieties
Adequate ventilation
Removal of infected leaves

⚠️ Before you reach for a spray

This atlas is informational and still growing — different diseases can look almost identical. Confirm the diagnosis and read the product label before applying any plant protection product. If you are unsure, ask your local extension or advisory service.

Keep the disease atlas with you in the garden

In the app you can identify a disease from photos, work out the spray dose for your own bed and log the treatment in your task calendar. Free, no sign-up, works offline.

Open the atlas in the app →

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