Plant guide:ð
Tomato
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â ModerateA sunken, leathery dark patch at the blossom end ïŋ― caused by calcium-transport disruption from inconsistent watering.
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Growth
Blossom End Rot on Tomatoes
Commonly affects: Solanum lycopersicum (Tomato)
A sunken, dark brown to black leathery patch develops on the bottom of the fruit, opposite the stem. The rest of the tomato looks otherwise normal, and the lesion doesn't spread as fuzzy mould, though it can allow secondary rot to move in.
Potential Causes
- 1Calcium deficiency in the developing fruit, usually triggered by inconsistent watering rather than a true soil shortage
- 2Rapid growth after a dry spell followed by heavy watering, disrupting calcium transport
- 3Root damage from overly aggressive cultivation near the plant base
- 4High salt levels or excess nitrogen interfering with calcium uptake
Solution Steps
- 1Remove affected fruit, since they won't recover, letting the plant redirect energy elsewhere.
- 2Water deeply and consistently, aiming for even soil moisture rather than a dry-then-flood pattern.
- 3Mulch around the base of the plant to help retain consistent moisture.
- 4Apply a calcium supplement such as gypsum or a foliar calcium spray as a precaution, especially in fast-draining container mixes.
Prevention Tip
Keep soil moisture even throughout fruit development ïŋ― a consistent watering schedule prevents blossom end rot far more reliably than added calcium alone.
