Growing Broccoli in Containers

Quick facts

  • Best type for pots: calabrese, ideally a compact variety such as 'Kabuki'

  • Container: at least 30 cm wide and 30 cm deep for one plant; around 40 cm across is better

  • Plants per pot: one for the biggest heads, two for smaller heads and more side shoots

  • Compost: multi-purpose compost

  • Harvest: three to four months after sowing, then side shoots for several weeks

  • Key moment: keeping the pot watered, as calabrese that dries out flowers early

Broccoli isn't the first crop most people think of for a patio, but calabrese, the kind with one big green head, grows well in a large pot. A single plant gives you a main head and then a run of smaller side shoots. Pots also let you grow broccoli in fresh compost if your garden soil has clubroot.

Calabrese or sprouting broccoli?

  • Calabrese is the better choice for containers. It grows to about 60 cm, crops within three or four months of sowing, and compact varieties are bred for small spaces.

  • Sprouting broccoli grows up to 90 cm tall and nearly as wide, and it stays in the pot from spring right through to the following spring. It's only worth trying in a very large tub with a strong cane for support.

Choosing a container

  • Size: at least 30 cm wide and 30 cm deep for one plant. A pot around 40 cm across gives the roots more room and dries out more slowly.

  • Weight: choose a heavy pot, such as terracotta, glazed ceramic or a sturdy tub, so it doesn't tip over as the plant gets top-heavy.

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

Grow bags aren't suitable. They're too shallow for broccoli to root firmly, and the plant rocks loose as it grows.

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

Choosing a variety for pots

'Kabuki' is a compact calabrese with an RHS Award of Garden Merit, bred for small spaces and good for autumn heads. 'Green Magic', also an Award of Garden Merit variety, matures early and produces plenty of side shoots after the first cut, which suits a pot well.

Sowing broccoli in containers

Calabrese dislikes being moved, especially in warm weather, so sowing straight into the final pot works well:

  1. Fill the pot with multi-purpose compost and water it.

  2. Sow two or three seeds in the centre, about 2 cm deep.

  3. When the seedlings come up, keep the strongest and pull out the rest.

Sow from April to June. You can also start seedlings in modules in March and April, then move them into their pot when they're 10–15 cm tall.

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

Planting young broccoli into pots

If you raised seedlings in modules or bought young plants, plant them before hot weather arrives. Ease them out without breaking up the rootball, and set them deeper than they were growing, with the lowest leaves at compost level. Firm the compost around the stem and water well.

Watering container broccoli

This is where most container broccoli goes wrong. Compost dries out quickly, and calabrese reacts to drying out by flowering early, before the head is full size. Check the pot every day or two in summer and water whenever the top few centimetres feel dry, especially once the head starts to form.

For more detail, see how often to water broccoli

Feeding container broccoli

The nutrients in potting compost run low after a few weeks. When plants are about 20 cm tall, start giving a high-nitrogen liquid feed every couple of weeks to keep the leaves and head growing.

Where to put container broccoli

Stand the pot in sun or very light shade, somewhere sheltered from strong wind. As the head forms, the plant gets top-heavy, so push a cane into the pot and tie the stem to it.

Protecting container broccoli

Pigeons, cabbage white caterpillars and aphids find broccoli in pots just as easily as in a bed. Cover the pot with fine insect-proof mesh held up on canes or hoops from planting.

For growing cabbage the same way, see growing cabbage in containers

Harvesting container broccoli

Cut the main head when it's firm and the buds are still tightly closed, before any yellow flowers show. Leave the plant in the pot, keep watering and feeding, and pick the smaller side shoots as they form over the following weeks.

For more detail, see when to harvest broccoli

If your plants aren't producing heads, see why broccoli doesn't form heads

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

Common questions

Can you grow broccoli in pots?
Yes. Calabrese grows well in a pot at least 30 cm wide and deep, and compact varieties such as 'Kabuki' are ideal. Sprouting broccoli is usually too big for containers.

What size pot does broccoli need?
At least 30 cm wide and 30 cm deep for one plant. A pot around 40 cm across is better, as it holds more water and gives the roots more room.

How many broccoli plants per pot?
One plant per pot gives the biggest head. Two plants in a larger pot give smaller main heads but plenty of side shoots.

Can you grow broccoli in a grow bag?
No. Grow bags are too shallow for broccoli to root firmly, and the plant rocks loose as it gets taller.

Varieties, sowing, planting and care based on RHS guidance.

 
laura tennant