Tomato and Zucchini Problems: Bacterial Spot, Aphids, and Blossom End Rot

Three Separate Issues

Tomatoes with yellow curling leaves, black spots, tiny red bugs, and zucchini with yellow leaves and blossom-end rot represent distinct problems:

1. Tomato Bacterial Spot

Black spots + curling = bacterial spot (Xanthomonas). Fungicides don't work. Spray Hi-Yield Copper Fungicide (bactericidal)—safe, 0-day pre-harvest. Repeat 7–10 days if spreading or after rain.

2. Tomato Aphids

Tiny red bugs = aphids. Sevin dust fails because aphids feed on leaf undersides. Use liquid Sevin sprayed upward on undersides (3-day PHI) or neem oil.

3. Zucchini Blossom-End Rot

Fruit rotting from blossom end = calcium deficiency + water fluctuation. Apply calcium nitrate (1 tbsp/plant, 3–4" from base). Maintain even soil moisture—no wet/dry cycles. Bone meal too slow.

Integrated Approach

• Copper for bacteria.
• Underside spray for aphids.
• Calcium nitrate + steady water for zucchini.

Each problem has a specific, effective fix.