Best Fertilizer for Tomatoes with Fruit Rot: Calcium and Phosphorus Focus

Nutrient Targets for Tomatoes

• High phosphorus (middle number) → fruit size/yield.
• Calcium → prevents blossom-end rot.
• Moderate potassium → stem strength.
• Low nitrogen → avoids leafy excess.

Recommended Ratio

10-20-20 or similar (e.g., 5-10-10, 4-8-12). Tomato-specific formulas (Miracle-Gro Tomato, Espoma Tomato-tone) include calcium.

Organic Alternatives

• Fish emulsion + kelp (biweekly).
• Bone meal (P) + gypsum (Ca) at planting.
• Compost tea weekly.

Avoid

High-N fertilizers (10-10-10, 20-20-20, lawn food). They cause rot indirectly via rapid growth + calcium dilution.