Tomato – Preventing Blossom-End Rot in Tomatoes

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AI Farming

May 19, 2025

Nothing is more frustrating than watching your beautiful tomatoes start to ripen — only to find a sunken, dark patch forming on the bottom. That’s blossom-end rot, and while it looks like a disease, it’s actually a physiological disorder caused by a calcium imbalance.

What Causes Blossom-End Rot?

Blossom-end rot typically strikes when:

  • The plant can’t absorb enough calcium from the soil
  • There’s inconsistent watering, leading to poor nutrient uptake
  • The plant grows rapidly during early fruit set, outpacing its ability to distribute calcium

The result? A leathery brown or black spot at the blossom end of the tomato. It ruins the fruit, and if not addressed quickly, it can affect several tomatoes on the same plant.

How to Prevent It

  • Water consistently: Avoid letting soil dry out completely, then overwatering. Keep it evenly moist.
  • Mulch to regulate moisture and temperature.
  • Avoid high-nitrogen fertilizers, which promote leafy growth over fruit support.
  • Test your soil: Ensure it has enough calcium (bone meal or crushed eggshells can help, though long-term solutions are better).
  • Don’t over-prune during fruit set — the plant needs stable nutrient flow.

Once a fruit shows blossom-end rot, it won’t recover — remove it so the plant can focus energy on healthy ones.

Stay ahead with AiFarming: Our platform tracks moisture fluctuations, provides nutrient alerts, and warns you when blossom-end rot conditions are likely. Think of it as your early warning system — before the damage is done.

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