The short answer
Water container tomatoes deeply whenever the mix begins to dry. Check daily in hot weather because a large fruiting plant can use water quickly, but do not water an already wet pot.
Why this happens
Containers dry faster than garden beds, and small pots magnify moisture swings. Consistent moisture supports fruit development and reduces stress associated with blossom-end rot.
What to do
- Use a generous container with drainage holes.
- Check moisture beneath the surface each day in warm weather.
- Water slowly at the soil level until excess drains out.
- Recheck during heat waves and mulch the soil surface if suitable.
Keep in mind
A saucer left full of water can suffocate roots. Wilting during peak heat does not always mean the soil is dry; check first.