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Tomato Seedling Sunburn After Moving Outdoors

Tomato seedlings started indoors, moved outside a week ago, now have white, dying leaves: classic sunburn (photoinhibition) from sudden UV exposure. Plants lack protective pigments and thickened cuticles.

Recovery

Move to shade or dappled light immediately.
Gradually increase sun exposure over 7–10 days (hardening off).
Damaged leaves won't recover; new growth will be normal.

Prevention

Always harden off seedlings: start with 1 hour morning sun, increase daily. Cloudy days are ideal for transition.

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