Solving Yellow Tomato Leaves in Florida: Whiteflies, pH, and Sanitation

Diagnosing the Yellowing

Central Florida tomatoes with yellow, curled leaves + insects = likely Sweetpotato Whitefly (Bemisia tabaci) infestation. Whiteflies suck phloem sap, removing photosynthesis products → yellow, deformed leaves. They also vector viruses.

Integrated Management

1. Insecticidal soap or horticultural oil: Weekly, thorough coverage (undersides!). Early morning.
2. Yellow sticky traps: Monitor and reduce adults.
3. Reflective mulch: Silver plastic or aluminum foil disorients whiteflies.
4. Beneficials: Release Encarsia formosa or Eretmocerus eremicus (parasitic wasps) weekly.
5. Remove heavily infested leaves (bag, trash).

Container Sanitation (Critical for Replanting)

• Discard old potting mix (compost away from garden).
• Scrub pots with brush + soapy water.
• Soak 30 min in 10% bleach solution (1:9 bleach:water).
• Rinse thoroughly; air dry in sun.
• Use fresh, sterile potting mix.

Soil pH and Nutrition

• Target pH 6.0-6.8. Test mix; amend with lime (raise) or sulfur (lower).
• Calcium deficiency (blossom end rot) common in containers—add gypsum or calcium nitrate.
• Balanced organic fertilizer (5-5-5 or tomato-specific) at planting + monthly.

Watering Practice

Morning watering at soil level (not foliage). Consistent moisture—self-watering containers or drip irrigation.