How to Grow Brussels Sprouts

How to Grow Brussels Sprouts

'Brigitte F1' has to be the best and most reliable brussels sprout variety with fantastic results every time. We recommend using an F1 hybrid sprout like Brigitte because the sprouts stay closed longer giving you a broader harvesting period.

how to grow brussels sproutsBrussels Sprouts, so called because they were very popular in Belgium, are best known today as the least popular part of the Christmas lunch. Yet they are delicious if cooked properly and are an excellent source of vitamin C, vitamin D, folic acid and dietary fibre.
Brussels sprouts contain health-promoting compounds called glucosinolates which may help to prevent cancer, so we can call them a 'super food'.

Brussels Sprouts are a slow growing vegetable, taking 26 to 31 weeks to reach maturity and produce a crop of sprouts. However, there are few other vegetables that can be enjoyed fresh from September right through February.

Brussels sprout plants

Where to Grow

Sprouts are hardy plants and will grow in most sites but will need to be staked in Autumn in exposed areas to prevent blowing over in high winds. Soil should be very fertile with plenty of garden compost and well rotted manure added. Ground is better prepared the previous Autumn and allowed to settle as sprouts need a firm soil to produce good sprouts.

When to Grow

If you choose staggered planting dates sprouts can be harvested for a long period from September to February. Sow in modular trays in mid March, early April and early May and plant out 4 weeks later.

Crop Rotation

Sprouts belong in the Brassica section of your rotation plan.


Brussels sprouts are best sown in a modular seedling tray and planted out 4 weeks later. Sow 1 seed per module at 2cm deep in an 84 cell plant tray. They will germinate in 7-12 days and be ready to plant out about 4 weeks later. If the plants are on a heat bench or in a propogator and they are looking spindly, turn the heat down and try to give them as much light as possible. If 2 sprouts have been germinated in any of your modules you need to remove the weaker one. Don't pull the seedling out as you'll damage the roots of the one you want to keep. Nip the unlucky one with your finger nail or cut with a scissors. Watering. It's important to keep you seedlings properly watered before you plant them out in the gartden. You are actually far better to under rather than overwater your plants. This may sound odd but making the roots serch for water helps to develop a better root system. It's a bit like keeping fit. You do need to be careful, however, not to let the compost plug completely dry out or it will form a crust on top and won't absorb the moisture the next time you water. It will all depend on the weather of course but on a hot day you will need to water twice a day, if it's it's dull every 2 days will be fine.

Hardening Off

Plants that have been raised indoors will need to get used to the outdoor temperature and conditions before they can be planted outside, this will take about a week to 10 days depending on the weather. The best way is to use a cloche or mini greenhouse. You can leave the cloche off the plants on dry frost free days and replace at night. Gradually increase the time with the cloche removed until the end of the week when can you leave it off day and night. If the weather is mild you may not need the cloche, just move the plants outside for longer periods each day. If you have started your seeds on a windowsill you will need to leave them in an unheated room for a day or two before moving outside to the cloche.


Brussels Sprouts plants are large and need a much larger planting space than you would think. Tall varieties of sprouts need 90cm between plants and 90cm between rows, smaller varieties need a spacing of 70cm between plants and 70cm between rows.

Brussels sprouts seedling plants

Make a hole in the soil with a trowel or dibber slightly deeper than the seedling root ball. Plant the seedling up to the level of the first true leaves and push the soil in around the plant with your fingers (The true leaves are the second set of leaves produced after the initial rounded seed leaves). The idea is to get a firm connection between the root ball and surrounding soil, the movement is pushing soil in around the plant horizontally rather than pushing down from the top.

Planting a brassica seedlingSprouts need a very firm bed so firm down well around the plant with the sole of your boot.

Seedling plants can be planted up the the base of the first set of true leaves if the stem has got a little leggy from lack of light at the seedling stage. The true leaves are the second set of leaves produced after the initial rounded seed leaves. A light sprinkle of seaweed/poultry manure around the planting hole will help your broccoli get off to a good start. Water it in well if rain is not likely in 24 hours.

Crop Care

Keep your sprouts well watered in dry weather, all brassicas prefer a moist soil. Sprouts are also a hungry crop so apply a feed every 4 weeks or so. Our 'Seamungus' seaweed-chicken manure pellets are an excellent source of nitrogen which will be perfect for leafy crops like cauliflower. If you want to give the plant a quick boost a liquid seaweed feed is ideal. Hoe regularily to control weeds and to stimulate the growth of the plant. One of the best gardening tools you'll ever buy is the oscillating stirrup hoe. It's a very effective old fashioned tool that really works properly. Hoeing not only removes the weeds but it also breaks up the surface of the soil and creates a fine texture or 'tilth'. A good tilth lets air and moisture in to the roots of your plants thus increasing their vigour.

Stake plants in Autumn and earth up around the roots to prevent them rocking or getting blown over. Drive a 2 inch post in beside the plant and tie with a soft tie or garden twine.

Pests and Diseases

See below for the most common symptoms of broccoli pest and disease:

Cabbage Root Fly

Look out for blue tinged leaves which wilt in sunny weather. Recent transplants are most vulnerable and will die, when plants are lifted you will find small white maggots around the roots. Use cabbage collars fixed around the plant stems or cover the crop with protective mesh or fleece.

Cabbage white butterfly caterpillar

Cabbage Caterpillars

Cabbage caterpillars are active between may and October and lay clusters of yellow eggs under the leaves. When the eggs hatch the caterpillars will start tucking into your plants so it's easier to check the underside of the leaves periodically (or if you see white butterflies hovering around plants) and brush of eggs. To prevent butterflies laying eggs protect the plants a fine insect mesh.

Leather Jackets & Cutworms

Stems are severed at ground level resulting in the death of seedling plants. Leather jackets and Cutworms are a similar grey/brown colour and live below the surface of the soil where the emerge from at night. If you find one severed stem search the soil in the vicinity and you are likely to find the culprit. To control use a nematode based natural insecticide.

brassica clubroot disease


Stunted growth especially if infected as seedlings. Discoloured leaves which wilt. Roots are a thick distorted mass. Clubroot likes acid soil so adding ground limestone or calcifies seaweed will help prevent it's spread. If discovered avoid planting any member of the brassica family for 7-9 years. Isolated gardens rarely have clubroot, it can only enter through infected transplants or walking in infected soil.


These are greenfly and blackfly which will be clearly visible on the leaves and especially organic fatty acid based pest control spray.

Blown Sprouts

Blown sprouts are open leafy sprouts rather than nice tight buttons. The causes are not enough well rotted organic matter in the soil, unsettled ground before planting and not firming down the seedlings enough when planting out. The condition is far less likely to occur with an F1 hybrid variety like brigitte F1.

Harvesting Sprouts

Spouts ripen from the base of the stalk, start picking from the bottom and work your way up. Remove any yellowing leaves as you go as they can harbour disease and restrict airflow around the ripening sprouts.

Harvesting brussels sproutsIf you're heading up to the in-laws for Christmas and have told them you're bringing your homegrown sprouts harvest cut the whole stalk, they'll keep longer. Dig up the root and preferably burn rather than compost to avoid encouraging club root.