Broccoli is easy to grow and yields quickly, providing you with a delicious, nutritious crop of blue-green heads, which can be harvested from summer to autumn, depending on when you sowed the seed. Sprouting broccolis are hardy and can can be harvested from March, further extending the growing season.
Broccoli is a popular vegetable, thanks to its vitamin content and its versatility in the kitchen. It can be used in anything from salads to curries, as well as steamed and served as a side dish.
How to grow broccoli
Sow seeds in modules of peat-free compost, every six weeks from spring to autumn. Thin seedlings and plant out when they’re large enough to handle. Grow in well-prepared, fertile alkaline soil, and keep well watered.
As with all brassicas, consider growing broccoli in a mesh cage to protect from cabbage white caterpillars. Harvest when the heads look ready to eat. Start with the central stem and then move on to harvest the side shoots.
More on growing broccoli
How to sow broccoli seed
If you have a greenhouse, you can start sowing broccoli seeds in modules or small pots, from late winter. Otherwise sow from early spring. For a steady crop across the season, sow seeds every six weeks.
Sow two seeds per pot or module. Thin to the stronger one when the seedlings have appeared and keep watering and feeding until the plants have four or five leaves. By this stage your broccoli plants are ready to plant out.
How to plant out broccoli
Broccoli does best in fertile alkaline soil, in full sun. Add slow-release fertiliser or well-rotted compost or manure to prepare the beds. Plant broccoli 30cm apart and 45cm between rows, so there’s plenty of space for side shoots to develop. Firm in well. Water regularly and feed with a high nitrogen fertiliser every two weeks.
Watch Monty Don prepare the soil for planting out broccoli.
Harvesting broccoli plants
Depending on the type of broccoli you’re growing, you can start cutting spears about 12 weeks after sowing. Cut the main, central head, first, which will trigger the development of side shoots. Then continue to cut side shoots regularly over the next four to six weeks.
Growing broccoli plants: problem solving
Broccoli is prone to the many problems that commonly affect plants in the brassica family.
Birds can demolish crops by eating young plants, so it’s a good idea to net crops.
The caterpillars of large and small white butterflies can cause damage, making holes in the leaves and eating into the heart of the plant. You can pick caterpillars off by hand or use insect-proof netting. However, you may find that wasps take most of the caterpillars from the plants to feed their young, and the plants recover after the caterpillars have completed their lifecycle. You can also grow nasturtiums as a ‘catch crop’, transferring caterpillars from your brassicas onto the nasturtium leaves.
Club root is a soil-borne disease occurring mostly in the warmer months. It infects the roots, causing them to become swollen, affecting the growth of the broccoli plants above ground. Improving drainage can help, as can adding lime to make the soil more alkaline. If your plants are affected, don’t grow brassica plants.
Preparation and uses
Broccoli is best steamed or lightly blanched. It can be used in stir fries, in salads or as an accompaniment to pasta.
See some of the recipes using broccoli, from our friends at Olive Magazine.
Broccoli is best used as soon after picking as possible, to make the most of the vitamins and minerals. It can be blanched and frozen.
Use the traditional methods of crop rotation to get the most out of broccoli plants. Plant out young broccoli seedlings in the beds where you were previously growing beans. The soil will be much improved by the nitrogen fixing properties of the legume family and this is great for ensuring healthy leaf growth in plants in the Brassica family.
Broccoli varieties to grow
- Broccoli ‘Green Magic’ RHS AGM – an early maturing variety with a good flavour and rust resistance
- ‘Brokali Apollo’ – a cross between broccoli and Chinese kale, with tasty, tender stems similar to those of sprouting broccoli
- ‘Early White Sprouting’ – white-sprouting broccoli has a slightly milder flavour than purple or green
- ‘Early Purple Sprouting’ – purple-sprouting broccoli is tasty and nutritious and the leaves are also edible
- ‘Belstar’ RHS AGM – with small, domed heads, good flavour and colour, this will produce lots of side shoots when main head has been cut