Planning reference

Blossom-End Rot vs Sunscald

Separate dark blossom-end fruit lesions from pale sun-facing patches before changing calcium, water, pruning, disease controls, or harvest decisions.

Problem diagnostic

Blossom-End Rot vs Sunscald cockpit

Start with lesion position, water swings, root injury, canopy loss, pruning history, direct sun, and whether affected fruit should be removed.

Fruit lesion location matters before adding calcium, pruning, spraying, or changing water.
  1. 1 Blossom-end rot clues Dark sunken lesion at the blossom end after uneven water or root stress.
  2. 2 Sunscald clues Pale blistered patch on the sun-facing side after foliage loss or exposure.
  3. 3 Fruit proof Location, water swings, canopy cover, pruning, and removal timing decide.
Lesion check
Location firststart with blossom end, stem end, or sun-facing side
Water proof
Even rootsuneven moisture moves calcium poorly into fruit
Canopy cue
Leaf coverfoliage loss exposes fruit to sunscald

What each fruit signal means

Blossom-end rot
Blossom-end rot is a physiological fruit disorder where low calcium in developing fruit, uneven water movement, salt stress, or root injury causes brown to black leathery decay at the blossom end of tomatoes, peppers, squash, cucumbers, or melons.
Sunscald
Sunscald is direct sunlight injury on exposed fruit, usually after disease, insects, over-pruning, or weak foliage lets hot sun hit green or ripening tomatoes, peppers, melons, or squash.
Dark blossom-end lesions
Dark blossom-end lesions start opposite the stem, often on enlarging fruit, and become sunken, leathery, brown, or black; adding pesticides will not fix this non-pathogen problem.
Pale sun-facing patches
Pale sun-facing patches form on the side of fruit exposed to direct sun, can look white, yellow, blistered, flattened, or papery, and are common after leaf loss exposes fruit that had been shaded.
Water balance, foliage cover, and fruit removal
Blossom-end rot prevention depends on even root-zone moisture, mulch, soil-test-based fertility, and avoiding root damage, while sunscald prevention depends on healthy foliage cover and removing affected fruit before decay spreads.

Fruit damage workflow

Check lesion position before changing inputs
Do not treat every damaged tomato, pepper, squash, or melon fruit the same way; check whether the lesion starts at the blossom end, faces direct sun, follows uneven watering, follows defoliation, appears leathery and dark, or appears pale and blistered before adding calcium, pruning, spraying, re-watering, or leaving affected fruit on the plant.
Stabilize moisture without saturating roots
For blossom-end rot, keep root zones evenly moist with deep watering and mulch, but do not swing from drought to saturation or cultivate close enough to injure roots.
Avoid fertilizer guesses
Use soil-test guidance before adding calcium, nitrogen, compost, manure, or salts. Blossom-end rot often reflects calcium movement into fruit rather than a simple lack of soil calcium.
Protect foliage that shades fruit
For sunscald, avoid over-pruning and manage defoliating insects or leaf diseases early so fruit are not suddenly exposed to intense sun during hot weather.
Remove fruit that will not recover
Fruit with blossom-end rot or sunscald will not heal normally. Remove badly affected fruit so the plant can redirect energy and secondary decay does not become the next problem.

Use these paths

Source basis