Plant guide:ðŸĨ’ Cucumber
Back to Plant Clinic
⚠ Moderate
ðŸĐš
Fungal

Powdery Mildew on Cucumber Leaves

Commonly affects: Cucumis sativus (Cucumber)

A white powdery coating spreads across leaf surfaces, starting on older leaves and expanding rapidly, weakening the plant and reducing fruit quality.

Potential Causes

  1. 1Podosphaera xanthii fungus, extremely common on all cucurbits
  2. 2Dense planting restricting airflow
  3. 3Warm days and humid nights favouring spread

Solution Steps

  1. 1Remove and destroy heavily affected leaves
  2. 2Apply a sulphur or potassium bicarbonate fungicide at first signs
  3. 3Improve spacing and airflow between plants
  4. 4Choose powdery-mildew-resistant varieties for future plantings

Prevention Tip

Powdery mildew is nearly universal on cucumbers by mid-season — resistant varieties reduce the problem more reliably than any spray programme.

More Fungal & Bacterial Disease Problems

See all →
Powdery Mildew — Erysiphe & Golovinomyces spp. — anthurium plant care

Powdery Mildew — Erysiphe & Golovinomyces spp.

Bacterial & Fungal Leaf Spot — Xanthomonas & Cercospora spp. — calathea plant care

Bacterial & Fungal Leaf Spot — Xanthomonas & Cercospora spp.

Anthracnose — Colletotrichum Leaf Blight — monstera plant care

Anthracnose — Colletotrichum Leaf Blight

Fusarium Wilt — Vascular Browning & Collapse — monstera plant care

Fusarium Wilt — Vascular Browning & Collapse

See how growers dealt with this →
Track this problem in your grow diary