When should I sow Brussels sprouts in the UK?

March to April. Earlier (February) sowings tend to bolt; later (May) sowings don't have time to mature decent sprouts before winter. Transplant the seedlings to their final position in June or July when they're pencil-thick.

Why are my Brussels sprouts loose and blown rather than tight?

Loose soil at planting time. Brussels sprouts need a firm, settled bed — they're top-heavy plants that rock in wind, and any movement at the roots produces blown (loose, open-leaved) sprouts. Tread the bed firm before transplanting; firm the soil hard around each plant; stake from autumn onwards.

Do Brussels sprouts really taste better after frost?

Yes, scientifically. Frost triggers the plant to convert starches to sugars as an antifreeze response, sweetening the sprouts dramatically. Pre-frost sprouts (September) tend to taste rough and earthy; post-frost (November onwards) they're sweet. The reason Christmas sprouts always taste better than September ones.

When do I pick Brussels sprouts?

From October when the lower sprouts are walnut-sized and tight; pick through to March the following year. Snap the bottom sprouts off first; work upwards over weeks. A single plant gives 30–50 sprouts spread over 4–5 months of picking — far better value than a single-harvest commercial-style crop.

What's the best variety for the UK?

For uniform commercial-style crops, F1 hybrids (Diablo, Trafalgar, Brigitte) give predictable results. For better flavour and a longer picking window, heritage varieties (Bedford Fillbasket, Long Island Improved) crop over a wider date range with variable sprout size. Most allotment growers split between an F1 (reliability) and a heritage cultivar (flavour).

My sprouts have aphids inside them — what do I do?

Mealy cabbage aphid (Brevicoryne brassicae) gets between the leaves of developing sprouts. Net against butterflies as standard; that doesn't stop aphids. For severe infestations, hose down the plants weekly with a soft soap spray (a teaspoon of washing-up liquid in a litre of water). Encouraging hoverflies and ladybirds (plant flowering dill, coriander, fennel near the brassica bed) is the long-term defence.

Brussels sprouts

Brassica oleracea var. gemmifera

vegetable☀️ full-sun🪴 clay loam📏 tallUSDA 3–7

📋Quick Facts

Height

0.9-1.2m

Spread

0.5-0.6m

Water

💧💧 Average watering

Hardiness

Zone 2-11

About

Sow Brussels sprout seed from March to April indoors or in a seedbed; transplant 60 cm apart in firm fertile soil from June to July. Brussels sprouts are very hardy (RHS H5–H6) and one of the longest-season UK crops — sown in March you're picking from October through to March the following year. Frost actually sweetens the sprouts; pre-frost picks taste rough. Net against cabbage white butterflies through summer and again against pigeons through winter. Stake firmly at planting — mature plants are top-heavy in autumn gales. Pick from the bottom up as sprouts mature; the leafy top stays on the plant until November to power growth.

Top tip

Firm soil and staking help; remove yellowing leaves and harvest sprouts from the bottom upwards.

Also known as: Spruitkool, Brassica oleracea var. gemmifera, Brukselka, Brussels sprouts, Rosenkohl, Choux de Bruxelles, Couves-de-Bruxelas, Cavolino di Bruxelles

How to grow brussels sprouts

1
Sow seed
March to April. Indoors in modules at 12–15°C, or direct in a seedbed once soil is workable. Sow thinly; germination in 1–2 weeks.
2
Prepare a firm fertile bed
Full sun, firm soil — Brussels sprouts hate loose ground because they topple later in life. Tread the bed firm; rake to a fine tilth. Brassicas prefer slightly alkaline soil (pH 6.5–7.0); lime if your soil is below 6.5.
3
Transplant when pencil-thick
June to July, when seedlings are 15–20 cm tall with 4–6 true leaves. Plant 60 cm apart in rows 75 cm apart. Bury the stem deeper than it was in the seedbed for stability. Firm the soil hard around each plant.
4
Net against cabbage white
From transplanting through October. Cabbage whites lay eggs on any brassica; caterpillars can strip a plant overnight. Use 5 mm enviromesh or fine butterfly netting on hoops.
5
Stake firmly
Tall varieties (Trafalgar, Diablo) reach 1 m and become top-heavy as sprouts develop. Bury the stem deep at transplant; tie to a stout cane from autumn onwards in exposed sites. Rocking damages the roots and reduces sprout size.
6
Don't pinch the top until November
The leafy top of the plant powers sprout development — keep it intact until at least November. Pinching the top earlier (topping) forces sprouts to mature simultaneously, which suits commercial growers but loses the long pick.
7
Pick from the bottom up
Sprouts mature first at the base of the stem. Snap the bottom sprouts off with a sharp downward twist when they're walnut-sized and tight. Work up the stem over weeks of picking. After cold frosts the flavour transforms — pre-frost sprouts are coarse; post-frost they're sweet.
8
Re-net for pigeons in winter
From October onwards, pigeons strip exposed brassicas. Re-tension or replace netting against pigeon damage. The cabbage white risk drops as butterflies die off; pigeon pressure peaks January–February.

Common questions

Pest Resilience

1/5 — Very vulnerable

Cabbage white caterpillars, mealy cabbage aphid, and pigeons all target them; whitefly too.

Companion Planting

Grows well with

Nasturtium Onion bulb Garlic Dill

Keep apart from

Wild strawberry Runner bean

Visual Characteristics

Fruits

Yes

Harvest: Autumn / fall to winter

🍳

Culinary

Culinary Use

Roasted, gratin, sautéed with bacon, steamed, stir-fried, hash

The brussels sprouts year in your garden

Dispatching imaginary bots to check your garden out...

What to do now

How to Propagate

🌰Seed

Easy

This plant produces viable seeds for propagation

Hardiness Zones

H1a (tender)H7 (very hardy)

H1a

H1b

H1c

RHS H5–H6

USDA 6 equivalent