RHS Growing Guides

How to grow Brussels sprouts

Our detailed growing guide will help you with each step in successfully growing Brussels sprouts.

  1. Getting Started
  2. Choosing
  3. Preparing the Ground
  4. Sowing
  5. Planting
  6. Plant Care
  7. Harvesting
  8. Problems
1

Getting Started

Getting Started
Choosing
Section 1 of 8

Hardy, robust and slow growing, Brussels sprouts are a classic winter vegetable, providing fresh, nutritious harvests in even the coldest weather. With modern varieties offering much improved flavour, this versatile veg has seen a revival in popularity and is now used in a wide range of dishes, not just the traditional festive feast.

Brussels sprouts will provide you with fresh, tasty harvests for Christmas and beyond
Slow but relatively easy to grow, Brussels sprouts provide valuable harvests through the leaner winter months. A member of the brassica (cabbage) family, they are very hardy and crop well through even the coldest winters. In fact, sprouts have the sweetest flavour when harvested after being frosted.

Brussels sprouts (Brassica oleracea (Gemmifera Group)) form large, quirky-looking plants about 90cm (3ft) tall, with a leafy top and sturdy stem covered in small rounded sprouts. This crop is slow to mature – sown from early spring onwards, it’s ready to harvest from autumn to late winter, depending on the variety and sowing time. While plants do take up quite a lot of space for a large part of the year, you don’t need many, as they should crop well, providing valuable fresh harvests across the winter months.

So why not try growing your own sprouts for a Christmas Day treat? Modern varieties have a mild, nutty, sweet flavour – far better than you may remember from childhood. Freshly picked sprouts are also full of health-boosting nutrients. Enjoy them lightly steamed, sautéed or stir-fried in all kinds of dishes.

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2

Choosing

Modern varieties have a sweeter flavour and can produce a large crop over a few months
There are more than 100 varieties of Brussels sprout to choose from, as well as a sprout/kale hybrid known as kalettes or flower sprouts. For consistently large crops of tasty, high-quality sprouts, it’s best to choose F1 hybrid varieties. Sprouts have a reputation for being rather bitter-tasting, but most modern varieties have been bred for improved flavour and sweetness. Look in particular for varieties with an RHS Award of Garden Merit (AGM), as these have been taste-tested by RHS experts and offer a mild flavour as well as a reliable crop – see our list of AGM fruit and veg (135kB pdf) and our Recommended Varieties below.

There are early, mid- and late-season varieties of Brussels, so if you have plenty of space you can grow a selection for harvesting from autumn through to late winter. Alternatively, you can concentrate on mid- to late-season varieties, for harvesting at Christmas and beyond, when other vegetables are in short supply.

Brussels are generally tall plants (many reach a height of about 90cm (3ft)), but there are more compact varieties that are better for windy locations, smaller gardens and containers. They can vary in colour too, so if you want a change from traditional green, there are attractive purple or red varieties such as ‘Red Bull’ and ‘Falstaff’. Some varieties also offer resistance to club root disease, while others are suitable for partial shade as well as full sun.

You can see many crops, including Brussels sprouts and other brassicas, growing in the veg plots at the RHS gardens, so do visit to explore how they are grown, compare the varieties and pick up useful tips and inspiration.

What and where to buy

Seeds of Brussels sprouts are widely available from garden centres and online gardening retailers. Young plants may also be available in spring and early summer from the same sources, but the choice of varieties will be more limited.

Recommended Varieties

Showing 3 out of 5 varieties
3

Preparing the Ground

Brussels sprouts like a sunny location with fertile, well-drained, firm soil. They form quite tall plants, so choose a sheltered spot where they won’t be buffeted by strong winds. If your soil is very acidic, apply lime the winter before sowing to raise the pH to at least 6.5; this will deter club root disease. You can carry out a simple pH test to find out the pH level of your soil.

Before sowing or planting, weed the ground thoroughly and dig in plenty of well-rotted manure or garden compost – about two buckets per square metre/yard. If you can do this the autumn before planting, this will allow plenty of time for the ground to settle. If not, be sure to firm the soil well by treading it down using shuffling steps, then rake it smooth.

Alternatively, if you're practicing no-dig, mulch the soil with organic matter ahead of sowing or planting directly into the mulch.

4

Sowing

Brussels need a long growing season, so start them off early, either indoors or outside under cloches. Sow early, mid-season and late varieties to provide harvests over the longest period. Brussels sprouts are brassicas, so should be grown with other cabbage relatives in crop rotations, to reduce the potential build-up of soil-borne problems.

Sowing indoors

For an early crop, sow from February to April in modular trays in a greenhouse or coldframe or on a sunny windowsill. Sowing indoors is also beneficial if you have club root disease in your soil, as the plants will develop a strong root system before being moved into the ground, so should be less severely affected. It’s best to use a modular seedtray, to minimise root disturbance when transplanting later. Fill it with peat-free seed compost, water to dampen thoroughly, then sow two seeds per module, 2cm (¾in) deep. 

Seedlings should appear in a couple of weeks. Thin them out to one per module, removing the smaller or weaker one. Keep them in bright light and water regularly. Move the young plants outside from April onwards, once they’re at least 10cm (4in) tall and have a good root system – see Planting below.

Sowing outdoors

Sow seeds from early March to May, into prepared ground (see above). If the weather is still cold, cover with cloches or biodegradable fleece. Brussels are traditionally sown in a separate ‘seedbed’, rather than in the main veg plot, then transplanted in early summer once more space becomes available. This is because these plants are slow to grow and would take up a lot of room during the prime spring season. However, you may prefer to sow straight into the final growing site, to avoid transplanting.

If sowing in a seedbed, sow the seeds thinly, 2cm (¾in) deep, in rows 15cm (6in) apart. Protect seedlings from slugs and snails and thin out to 7.5cm (3in) apart, removing the weaker ones. Young plants will be ready to move to their final growing site in early summer – see Planting, below.

If sowing in their final position, sow a few seeds every 60cm (2ft), then thin out the resulting clusters to leave just the strongest seedling at each point. Allow at least 60cm (2ft) between rows. Alternatively, sow seeds thinly along the row and thin the seedlings to 7.5cm (3in) apart, then in early summer thin them again to their final spacing of 60cm (2ft) apart, moving the spare plants to form new rows or fill any gaps.

For more sowing tips, see our guides below. 

Sowing in containers

If your soil is affected by club root, or you’re short on soil space, you could grow a compact variety in large containers of peat-free multi-purpose compost – one plant in a pot at least 30cm (1ft) in diameter. These plants need plenty of space to grow well, so don’t be tempted to plant more densely. You can either sow the seeds in modules indoors (as described above), then in early summer transplant individually into large containers, or sow several seeds in the centre of the large container outdoors, then thin out to just one strong seedling.

Related RHS Guides
Vegetables in containers

5

Planting

Make sure young plants have a good root system before transplanting them
In late spring or early summer, once young plants are 10–15cm (4–6in) tall, move them to their final growing position. This applies to plants sown in a seedbed, grown from seed indoors or newly bought young plants. Harden off indoor-sown plants first, to acclimatise them to outdoor conditions.

Prepare the ground as detailed above, and water the young plants well the day before moving. Then carefully lift each plant individually, 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 they root in deeply. Firm each plant in and water well.

Space plants 60cm (2ft) apart, with at least 60cm (2ft) between rows. This wide spacing is crucial, to give the plants plenty of light and air, which helps them to crop successfully and deters fungal diseases, so don’t be tempted to plant more closely. Protect the young plants from slugs and snails and cover with fine-mesh netting to avoid insect and bird damage.

Related RHS Guides
Vegetables: transplanting

6

Plant Care

Brussels sprouts become top-heavy, so you may need to provide extra support
Brussels sprouts are in the ground for a long time, so check plants regularly for any signs of problems. Water if the soil starts to dry out and remove fading leaves to improve airflow around the plants, which helps to deter fungal diseases. Keep cabbage butterflies and pigeons at bay with fine-mesh netting.

Watering

Water young plants regularly, never letting the soil dry out. Once they’re well established and growing strongly, they should only need watering during dry weather or on very free-draining soil. See our water-saving tips below.

Mulching

Apply a thick layer of mulch, such as well-rotted manure or garden compost, around the plants to help hold moisture in the soil and reduce the need for watering. Mulch will also deter weed germination.

Feeding

On poor soil, or to boost slow growth, you can apply a nitrogen-rich fertiliser in June or July.

Weeding

Keep young plants weed-free, to reduce competition for light, water and nutrients. Dense weeds can also provide shelter for slugs and snails. See our tips on controlling weeds.

Supporting plants

In late summer, mound up soil around the base of the stems, to provide extra support before autumn gales arrive. Taller plants may also need staking with a sturdy bamboo cane, especially in exposed sites. This will prevent wind buffeting these top-heavy plants, which can loosen the roots and hinder growth or even blow them over.

Protecting the crop

Brussels sprouts are vulnerable to the typical brassica problems, including pigeons and various insects, so keep plants protected at all times. The easiest option is to cover the crop with insect-proof mesh, supported on canes and pinned into the ground. See Problems, below, for more tips.
 
7

Harvesting

Pick when the sprouts are still bright green and tightly closed, ideally after frosty weather
Early varieties can be harvested from autumn onwards, but the main cropping season is through winter, as the flavour of the sprouts is sweeter 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’re the size of a walnut, firm and still tightly closed. Pick regularly, snapping them off with a sharp downward tug and taking a few from each plant along the row. Remove the lower leaves at the same time.

With newer varieties, the sprouts tend to mature more uniformly, so you can harvest the whole stem if preferred. There is usually no need to harvest all at once though – especially in cold weather, you can leave the plants standing and simply pick however many sprouts you need. Some varieties have better ‘standing ability’ than others. Just be sure to check plants often and harvest before the sprouts start to open or turn yellow. Once cropping is over, the mild-flavoured young leaves, or sprout tops, can be harvested too, and cooked like spring greens. 

If you cut the whole stem when harvesting, 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. 

8

Problems

Harvesting
Guide Start
Section 8 of 8

Brussels sprouts are generally hardy, robust plants, but they can suffer from the usual problems that affect the cabbage family. They are best grown under fine-mesh netting to protect them from insects and pigeons. If you have club root disease in your soil, start Brussels sprouts off indoors so the plants have a well-developed root system before they’re transplanted into the ground. For more on these and other issues, see our guide to Brussels sprouts problems and Common problems, below.

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