How to grow Brussels Sprouts

    Harvesting Brussels sprouts
    • Sow; March-May
    • Plant; May-June
    • Harvest; January-March, August-December

    Brussels sprouts are a popular vegetable in the cabbage (Brassica) family, and a staple part of the traditional Christmas lunch. Named after their popularity in Belgium, they are an excellent source of vitamins C and D, along with folic acid and dietary fibre. The vegetable also contains anti-cancer compounds called glucosinolates, which makes them a ‘super food’.

    Brussels sprouts are slow-growing, and can take up to 31 weeks to produce a crop. However, they crop from autumn through to spring, providing a valuable source of food in winter, when little else is available.

    How to grow Brussels sprouts

    Sow seeds in spring and plant out into fertile soil after all risk of frost has passed. Water regularly, feed with an organic nitrogen-rich fertiliser and stake in autumn to prevent wind rock. Harvest the sprouts as and when they are produced.

    Where to grow Brussels sprouts

    Potting on Brussels sprouts plants
    Potting on Brussels sprouts plants

    Brussels sprouts do best in moist but well-drained, fertile soil, ideally which has been enhanced with well-rotted manure or compost. Grow in full sun for best results.

    How to plant Brussels sprouts

    Brussels sprouts seedlings ready to be planted out
    Brussels sprouts seedlings ready to be planted out

    For a successive harvest, sow seeds every fortnight from March to May, in pots or modular seed trays – one seed per module or small pot – and keep them in an unheated greenhouse or cold frame. After around four weeks (or when seedlings are large enough to handle), transplant them into individual pots of peat-free compost. Then, from May onwards, when plants are 10-15cm tall, harden them off before planting out into well-prepared soil enriched with well-rotted horse manure. Space plants 60cm apart with 75cm between rows. Firm the soil around the plants thoroughly, as Brussels sprouts do best in firm soil. Water well and continue to water throughout the growing season, particularly in periods of drought. If cabbage root fly is a problem in your area, fix cabbage collars around the base of the stems.

    How to care for Brussels sprouts

    Staking Brussels sprouts
    Staking Brussels sprouts

    Feed fortnightly with an organic nitrogen-rich fertiliser. Prevent weeds from competing with the plants by hoeing regularly. Stake plants in autumn and earth up around the roots to prevent them rocking in high winds. Remove any yellowing leaves from the plants as they can harbour disease.

    Growing Brussels sprouts: pests and diseases

    Large white caterpillar on brassica leaf
    Large white caterpillar on brassica leaf

    Blueish leaves that wilt in sunlight: are likely to be cabbage root fly. Look out for white maggots around the roots. Use cabbage collars around the base of the stems to prevent further attack.

    Caterpillars eating the leaves: these are most likely the larvae of the large and small white butterfly (known as cabbage white butterflies). Gently transfer caterpillars to a sacrificial crop of nasturtiums, which are in the same family and will be readily eaten by both butterfly species.

    Stunted growth: this is most likely caused by clubroot, a fungal disease that thrives in acid soil and can remain in the soil for several years, reinfecting newly planted plants. Adding ground limestone or calcified seaweed can help prevent its spread, however if you do find clubroot in your garden or allotment it’s best to avoid growing brassicas for up to nine years.

    Blown sprouts: these are open sprouts as opposed to the tight ‘buttons’ you expect. Causes include poor and infirm soil.

    How to harvest Brussels sprouts

    Harvesting Brussels sprouts
    Harvesting Brussels sprouts

    Brussels sprouts ripen from the base of the stalk, so harvest them from the bottom as and when they are ready to pick. You can also cut the whole stalk as this will ensure the sprouts will keep for longer.

    Advice on buying Brussels sprouts

    • There’s a huge variety of Brussels sprouts to choose from, with early varieties ready from August and later varieties cropping until March
    • Ensure you have the right growing conditions for the plants, and remember they need rich, fertile soil to grow well

    Varieties of Brussels sprout to grow

    Brussels Sprout ‘Brodie’ F1 Hybrid – the supermarket Brussels sprout, with no bitterness. Height x Spread: 75cm x 50cm

    Brussels Sprout ‘Brilliant’ F1 Hybrid – firm buttons cropping from early autumn. Height x Spread: 75cm x 50cm

    Brussels Sprout ‘Bedford Fillbasket’ – bears large, firm sprouts with a good flavour. Height x Spread: 75cm x 50cm