Tomato Spotted Wilt Virus vs. Early Blight: How to Tell and What to Do

Brown Spots on Tomatoes and Geraniums — Different Problems

Your tomatoes show light brown, dried, spotted leaves. Geranium 'Rozanne' has similar spots. But they're likely different diseases.

Tomatoes: Three Main Culprits

• Tomato Spotted Wilt Virus (TSWV): Chocolate-brown spots on top leaves, burned/wilted appearance, uneven fruit ripening with ringspots. No cure — pull plants immediately.
• Early Blight (fungus): Spots start on lower leaves, concentric rings, yellow halo. Treat with copper fungicide or chlorothalonil.
• Bacterial Spot: Small, dark, water-soaked lesions on lower foliage. Copper sprays help.

Geraniums: Likely Bacterial Leaf Spot

Copper fungicide (e.g., Hi-Yield) has antibacterial activity — spray per label.

Critical Step: Identify Tomato Disease First

Use the pictorial guide: MSU Tomato Disease ID. Match your symptoms exactly.

• If TSWV: Remove plants, control thrips (vectors), don't compost.
• If fungal/bacterial: Treat accordingly, rotate crops next year.

Don't guess — misdiagnosis spreads disease.