Plant guide:ð
Tomato
Back to Plant Clinic
â ModerateSmall spots with dark borders and pale centres on lower leaves ïŋ― Septoria leaf spot, which overwinters in soil debris.
ðĐš
Fungal
Septoria Leaf Spot on Tomatoes
Commonly affects: Solanum lycopersicum (Tomato)
Numerous small, circular spots with dark brown borders and pale grey centres appear across lower leaves first, each spot often containing tiny black specks (fungal fruiting bodies) visible on close inspection. Heavily affected leaves yellow and drop.
Potential Causes
- 1Septoria lycopersici fungus, which overwinters in soil and infected plant debris
- 2Warm, wet weather with extended leaf wetness
- 3Splashing water spreading spores from soil onto lower foliage
Solution Steps
- 1Remove and destroy affected leaves promptly, working from the bottom of the plant upward as symptoms appear.
- 2Mulch around the base of the plant to reduce soil splash.
- 3Water at the base only, avoiding overhead irrigation.
- 4Apply a copper-based fungicide if the problem is recurring or spreading rapidly up the plant.
Prevention Tip
Clear all tomato debris from the garden at the end of the season, since Septoria overwinters in fallen leaves and soil, re-infecting new plants the following year.
