Leaf mold on tomato
The classic disease of tomatoes under cover (Passalora fulva, formerly Cladosporium fulvum). The upper leaf surface shows diffuse yellow patches, with a matching olive-brown, velvety growth underneath.
Symptom photos
Symptoms
- Diffuse, pale yellow patches on the upper leaf surface
- Olive-brown, velvety growth on the underside of those patches
- Leaves browning, curling and drying out
- Symptoms moving up from the oldest leaves
- Leaf drop when the attack is severe
What it does to the crop
- Loss of leaf area and a smaller crop
- Poorer coloring and smaller fruit
- Plants dying off early in the tunnel
- Rapid spread in humid air
What encourages it
- Humidity above 85% under cover
- Temperature 20-25°C with poor ventilation
- Crowded planting and leaves left unremoved
- Condensation settling on plants towards morning
Prevention
- Ventilate the tunnel hard, especially in the morning
- Remove lower leaves and thin out the canopy
- Drip-irrigate instead of overhead watering
- Grow varieties resistant to Passalora fulva
- Disinfect the tunnel structure after the season
⚠️ 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.
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