Do Bigger Pots Really Grow Better Tomatoes?
Root volume matters up to a point. Standard guidance is a minimum of about 10 litres per plant for containers, with larger volumes making watering and feeding far more forgiving.

The RHS advises growing tomatoes in large containers or growing bags, planting no more than two plants per standard bag, because restricted root volume dries out and starves plants quickly.
Container-grown plants need more frequent watering and a regular high-potassium feed once the first fruits set — the smaller the container, the less margin for error.
Erratic watering in small containers is associated with blossom end rot and fruit splitting, which is why volume behaves like a buffer rather than a growth stimulant on its own.
What we do not know
We are not aware of a public, controlled UK trial comparing yields across a range of pot sizes for named varieties under identical feeding. The Tomato Post has not run one. Any figures you see quoted as a precise yield gain should be treated sceptically.
Sources
- Tomatoes: grow your own — Royal Horticultural Society
- Blossom end rot — Royal Horticultural Society





