Brussels sprouts Growing Guide
Brussels sprouts are a hardy, robust, and slow-growing classic winter vegetable providing fresh, nutritious harvests even in the coldest weather. They are a member of the brassica (cabbage) family, forming large, quirky-looking plants about 90cm (3ft) tall, with a leafy top and sturdy stem covered in small rounded sprouts. Modern varieties offer much improved mild, nutty, sweet flavour, making them versatile for a wide range of dishes. They are slow to mature, with harvests from autumn to late winter, and are rich in health-boosting nutrients.
This guidance applies to the crop in general. Individual varieties and local conditions can differ.
Planting information
Sow seeds 2cm deep. Indoor Sowing: For an early crop, sow from February to April in modular trays in a greenhouse, coldframe, or on a sunny windowsill. Sow two seeds per module and thin to one stronger seedling. Keep in bright light and water regularly. Young plants can be moved outside from April onwards once they are at least 10cm tall and have a good root system. Outdoor Sowing (Seedbed): Sow seeds from early March to May into prepared ground. Cover with cloches or biodegradable fleece if the weather is cold. Sow thinly in rows 15cm apart. Protect from slugs and snails, and thin out seedlings to 7.5cm apart. Young plants are ready to move to their final growing site in early summer. Outdoor Sowing (Final Position): Sow a few seeds every 60cm, then thin out to leave just the strongest seedling at each point. Allow at least 60cm between rows. Alternatively, sow seeds thinly along the row and thin seedlings to 7.5cm apart, then in early summer thin them again to their final spacing of 60cm apart. Container Sowing: For compact varieties or if soil is affected by club root, sow seeds in modules indoors and transplant individually into large containers (at least 30cm in diameter) in early summer, or sow several seeds in the centre of the large container outdoors and thin to one strong seedling. In late spring or early summer, once young plants are 10–15cm tall, move them to their final growing position. Harden off indoor-sown plants first to acclimatise them. Prepare the ground and water young plants well the day before moving. Carefully lift each plant, trying not to disturb the roots. Set them in their new planting holes more deeply than before, with the lowest leaves at the soil surface, to ensure deep rooting. Firm each plant in and water well. Space plants 60cm apart, with at least 60cm between rows. Protect young plants from slugs, snails, insect, and bird damage using fine-mesh netting.
Harvesting information
Early varieties can be harvested from autumn onwards, but the main cropping season is through winter, as the flavour of the sprouts is sweetest once they’ve been frosted. The sprouts form on the main stem at the base of each leaf stalk. Start picking the lowest sprouts first, when they are the size of a walnut, firm, and still tightly closed. Pick regularly by snapping them off with a sharp downward tug, taking a few from each plant along the row. Remove the lower leaves at the same time. With newer varieties, sprouts tend to mature more uniformly, allowing for harvesting of the whole stem if preferred. Check plants often and harvest before sprouts start to open or turn yellow. Once cropping is over, the mild-flavoured young leaves, or sprout tops, can also be harvested and cooked like spring greens.
Storage information
If harvesting the whole stem, you can either stand it in water for a few days or hang it up in a cool, frost-free garage or shed, then pick the sprouts as needed.