The Problem Index → Garden
My tomatoes are rotting on the bottom
This is blossom end rot, it's a calcium delivery problem, and it is almost never a calcium shortage in your soil. Calcium moves with water, so the actual cause is uneven watering — which means the fix is free.
What actually works
✕ Avoid
Epsom salt for tomatoes
The most commonly recommended fix, and it pushes the wrong direction: magnesium competes with calcium for uptake.
$6 and a worse problem than you started with◆ Proven
Consistent soil moisture
Mulch heavily, water deeply on a schedule instead of in panic bursts. A soil moisture probe driving a drip valve ends it in most gardens by itself.
◆ Proven
A $15 soil test
If you want to know whether calcium or magnesium is genuinely short, this is the only way to find out rather than guess.
Run the numbers
- Irrigation requirement & run time → — free calculator, works offline.
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