Tomato Sunscald: Why Too Much Sun Can Be Hazardous to Your Tomatoes’ Health

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?

Photo: Colorado State University

  • 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 blister and 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?

Tomato sunscald with Tomato Dirt

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. You can also harvest sunscalded tomatoes and let them finish ripening on a windowsill or kitchen counter.

Can you eat tomatoes affected by sunscald?

Sure – as long as black mold hasn’t set in. To eat, simply slice off affected parts.

How can you prevent tomato sunscald?

Try some of these tips!

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