How to grow Vegetables - Brussels Sprouts

Brussels Sprouts

Brussels sprouts are part of the large Brassicaceae family (often called brassicas), which also includes broccoli, cauliflower, cabbage and kale.

They resemble miniature cabbages but have a sweeter flavour. They are high in protein, low in calories and rich in vitamins C, K and calcium. Antioxidants in Brussels sprouts can also lower glucose levels.

When it comes to Brussels sprouts, people either love or hate the taste of them. If they are a favourite in the kitchen, try stir-fried with bacon, shredded into a salad, roasted with garlic or simply served stemmed.

Follow our seven easy steps to successful Brussel Sprouts harvest including tips along the way.

Seven handy tips on how to grow yummy Brussels sprouts .

When to plant

Brussels sprouts can be tricky to grow as timing of planting is critical for the production of good sprouts. Sprouts take 4-5 months to form so late planting means sprouts are forming in spring as the weather is warming and days getting longer, and this spoils their development. If you have trouble raising seeds, start with seedlings to give your crop a head start.

Subtropic and tropic areas are not suitable as they are averse to hot dry weather.
In cooler areas, sow seed from spring to early autumn and seedling from autumn.
In temperate areas, restrict seed sowing to summer and seedlings from autumn.

Location

Brussels sprouts grow best in full sun or with light afternoon shade in hotter temperatures in soil that holds moisture well.
Sprouts can reach 1-1.2m high and are easily damaged by wind, so select a sheltered position.
Don’t choose a position in front of plants that need full sun as their foliage will put others in the shade.

Soil

Get the soil right to harvest a bumper crop of yummy Brussels sprouts.

Follow our steps for easy soil preparation.

Sprouts prefer a neutral to slightly alkaline soil so adding lime before planting is beneficial and ensures good growth.
Dig in compost or well-rotted manure before planting or apply Seasol Liquid Compost.
A soil rich in nutrients helps build strong plants so add Seasol Plant + Soil Booster (100g per square metre) and a fertiliser such as PowerFeed Controlled Release Tomatoes & Vegetables.
Water in well and let the soil rest for a week or two if possible.

Step 1 – Sowing seeds

Production and sprout formation is at its best when conditions are cool and days are shortening, which is why the timing of seed sowing is so critical to success.
In the ground, grow from seed sown directly in well-prepared, moist soil at a depth of 6mm. Space 60-70cm apart, pressing the seeds firmly into the soil and lightly cover.
In punnets, seed can also be sown into individual seed cells to transplant in around six weeks.
Water in well with Seasol GOLD or Seasol as this will help to increase seed germination rates. Soil should be moist but not wet, so check the soil moisture daily to ensure sprout seeds have the right conditions to germinate. Water if soil is dry.

Note: This is not Brussels sprout seeds, it’s just an illustration to show seeds being planted.

Step 2 – Germination.

Keep the soil or seed raising mix moist for the six to 10 days it takes for germination.
Brussels sprouts seeds germinate in warm to cool conditions however don’t expose seeds sown in pots or punnets to freezing temperatures. If any extra warmth is needed, stand the pots in a foam box.
Water gently and apply Seasol GOLD or Seasol weekly (mix 30mL of concentrate per 9 litres of water), as this will help to stimulate strong root development and healthy growth.
The first sign of growth is the appearance of a green shoot.
Protect emerging seedlings from snails and slugs that may like to eat them and cover as necessary to protect them.

Step 3 – Baby Brussel Sprouts seedlings.

Transplant seedlings into small individual pots when they are big enough to handle.
Allow them to grow on until they are around 7cm high and ready to be planted out into the garden.
Liquid feed with PowerFeed PRO SERIES for Tomatoes & Vegetables weekly to keep hungry seedlings strong, healthy and growing vigorously. Mix 20mL of concentrate per 9 litres of water (standard watering can) for young seedlings.
Check soil moisture daily and water as needed.

Step 4 – Planting out Brussels Sprouts seedlings.

If grown from seed, transplant seedlings when they are around 7cm high spacing seedlings at least 60cm apart and plant firmly into the soil.
When transplanting from seedlings that have been purchased follow the directions for planting on the planting tag.
Water in well with Seasol GOLD or Seasol as this will aid transplant shock and help with plant establishment for strong, healthy growth.
Soil should be moist but not wet, so check the soil moisture daily before watering. Protect seedlings from pests including birds and snails.

Step 5 – Brussels Sprout growth.

Keep the soil around developing plants hand weeded or hoed and well-watered.
Spread mulch around each plant to suppress weeds, help retain soil moisture and keep the root zone cool.
Every 6-8 weeks apply another application of PowerFeed Controlled Release Tomatoes & Vegetables. Remember to water it in thoroughly after application.
Keep plants upright and growing straight for best sprout formation. These tall plants may require staking especially in windy conditions.

Step 6 – Brussel Sprouts formation

Sprouts form on the stem of the plant. They don’t start producing sprouts until they reach almost full height. Each sprout grows in the leaf axil or joint.
Check carefully for caterpillars, aphids and earwigs.
Remove lower leaves to expose developing sprouts to allow sunlight and air to move around the plants.
Feed hungry plants with PowerFeed PRO SERIES for Tomatoes & Vegetables weekly. Mix 50mL of concentrate per 9 litres of water – standard watering can.

Sprouts mature from the base of the plant upwards over time.
Harvest when sprouts are round, firm and large – 2-3cm in diameter – usually 17-21 weeks from planting.
Break the sprouts, harvesting as needed or store in the crisper section of the fridge.

Tip: The stem left behind after harvest can reshoot forming delicious leafy ‘sprouts’.

Things to watch out for……

Aphids These tiny black or green pests cluster under leaves. Squash or hose off.
Cabbage white butterflies The green caterpillars of this small white butterfly feed on all brassicas. Squash any seen or apply an organic pesticide. Erecting netted tunnels over the rows prevents this pest from laying eggs on the leaves of the crop.
Earwigs This tiny dark brown pest hides and feeds among the leaves making holes in the sprout. Squash any that are seen. Traps made of screwed up paper in a jar can reduce numbers. Empty traps each morning.

Slugs and snails These pests can destroy young plants. Snails and slugs are active at night. Use iron-based, non-toxic baits.
Club root This is a fungal disease that affects growth and causes distorted swollen roots. Applying lime before planting reduces the likelihood of this disease.
Downy mildew This fungus can attack leaves. Look for yellowing discolouration above and white mildew below the leaves. Remove affected leaves.
No sprout formation If it is too hot or too dry, plants may grow but sprouts fail to form beyond marble size. Alternatively the sprouts become fluffy (called ‘blown’) but are still edible. Sow seeds in late summer and keep plants well watered.

How to grow Vegetables – Brussels Sprouts