Growing Cauliflower in Containers

Quick facts

  • Best choice for pots: mini cauliflowers, such as 'Candid Charm'

  • Container: about 40 cm across and at least 30 cm deep, with drainage holes

  • Plants per pot: up to four minis in a 40 cm pot, about 15 cm apart

  • Compost: multi-purpose compost

  • Harvest: when heads are about the size of a tennis ball

  • Key moment: steady watering, as a pot that dries out gives tiny button heads

Full-size cauliflowers are big plants that need 45–70 cm of space each, which makes them hard to grow well in pots. Mini cauliflowers are a much better fit. They're bred to grow close together and make small, neat heads, and several fit in one container.

Choosing a container

  • Size: about 40 cm across holds up to four mini cauliflowers. Choose one at least 30 cm deep so the compost doesn't dry out too fast.

  • Drainage: make sure there are holes in the base, and raise the pot on feet or bricks.

  • Material: a heavy pot or a sturdy tub stays steadier than lightweight plastic.

Grow bags aren't suitable. They're too shallow and dry out too quickly, and cauliflower reacts badly to drying out.

For more on choosing pots for vegetables, see growing vegetables in containers

Choosing a variety for pots

Look for varieties sold as mini cauliflowers. 'Candid Charm' is a quick-maturing mini summer cauliflower recommended by the RHS. Full-size varieties can be grown one to a very large tub, but the heads are usually smaller and the plants more likely to struggle.

Sowing and planting mini cauliflowers

Starting in modules (most reliable): sow one seed per module, about 1.5 cm deep, and keep the tray somewhere bright. Plant the young cauliflowers into their pot at about six weeks old, when they're 10–15 cm tall. Don't leave them in the modules any longer, as pot-bound plants are likely to make button heads.

Sowing straight into the pot: sow two or three seeds at each spot, 15 cm apart and about 1.5 cm deep, then keep the strongest seedling at each spot.

Either way, set young plants a little deeper than they were growing, with the lowest leaves at compost level, and firm the compost around them.

For sowing times, see when to plant cauliflower in the UK

Watering container cauliflower

This is the most important job. Cauliflower that dries out, even briefly, tends to make small, early button heads. Compost in a pot dries far faster than garden soil, so check it every day or two in summer and water whenever the top few centimetres feel dry. Keep it damp but not waterlogged, especially once the heads start to form.

For more detail, see how often to water cauliflower

Feeding container cauliflower

The nutrients in potting compost run low after a few weeks. Once plants are growing well, give a nitrogen-rich liquid feed every couple of weeks until the heads start to form.

Where to put container cauliflower

Stand the pot in a sunny spot, sheltered from strong wind. As heads form, snap a leaf or two and fold it over each head to stop the sun turning it yellow.

Protecting container cauliflower

Pigeons, cabbage white caterpillars and cabbage root fly all find cauliflower in pots. Cover the container with fine insect-proof mesh on canes or hoops from planting.

For growing a related crop the same way, see growing broccoli in containers

Harvesting container cauliflower

Cut mini cauliflowers when the heads are about the size of a tennis ball and still firm and tight. Check them every few days once they start to form, as heads can loosen quickly in warm weather. Each plant produces one head, so clear the pot and resow once they're all cut.

For more detail, see when to harvest cauliflower

If your plants aren't forming heads, see why cauliflower doesn't form heads

For the whole growing season, see how to grow cauliflower in the UK

Common questions

Can you grow cauliflower in pots?
Yes, but mini cauliflowers work best. Up to four fit in a pot about 40 cm across. Full-size cauliflowers need too much space to grow well in most containers.

What size pot does cauliflower need?
A pot about 40 cm across and at least 30 cm deep holds up to four mini cauliflowers spaced 15 cm apart.

Can you grow cauliflower in grow bags?
No. Grow bags are too shallow and dry out quickly, and cauliflower that dries out tends to make small button heads.

Why are my container cauliflowers so small?
Usually because the compost dried out or the plants were left too long in their modules before planting. Both cause button heads. Keep the compost damp and plant out at about six weeks old.

Container size, spacing, varieties and care based on RHS guidance.

 
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