Tomato sunscald is a problem caused by growing conditions – specifically intense, direct sunlight for extended periods during very hot weather. The excessive sunlight discolors patches on ripening or green tomatoes.
What does tomato sunscald look like?
- Sunscald first appears as light patches on green or ripening fruit
- Most often, sunscald develops on the side of the fruit that faces the sun
- As the patches grow, they may become grayish-white
- Affected sunscald tomatoes can develop black mold
When does sunscald affect plants?
When green or ripening tomatoes get too much direct sun, especially during very hot weather.
How can you control sunscald?
Sunscald is irreversible once it’s impacted a tomato, but its progression can be slowed. You can leave exposed fruit on the vine and cover it with lightweight screen, shade cloth, or straw to protect if from further damage.
How can you prevent tomato sunscald?
Choose heat-tolerant tomato varieties.
Cage tomato plants. Caging provides tomato support without requiring pruning, so foliage can provide shade to tomatoes, whereas traditional stakes and trellising expose fruit to maximum sunlight, which promotes sunscald.
Keep plants healthy and treat tomato problems as soon as possible. Tomato wilts, blights, and leaf spot cause plants to drop foliage, which expose fruit to excess sunlight.
When the forecast is for extended hot, dry weather, shield plants with a lightweight screen, shade cloth, or straw to protect fruit from over-exposure and hopefully prevent sunscald.
Consider growing tomato plants upside-down to shade fruit.