Independent comparisons. We may earn from shop links. More info

How to sow broccoli seeds in the UK

Updated: 21 October 2026

How to sow broccoli seeds depends on the packet. A generic March date is how people get bolted calabrese, or a spear plant in a bed wanted for September. Early Purple, Green Calabrese, Covina, and raab do not share one depth or one spacing. The packets are in the [broccoli seeds comparison](/hub/herb-seeds/broccoli-seeds). If you are unsure whether the foil is a head or a spear, read [calabrese vs sprouting broccoli](/hub/herb-seeds/broccoli-seeds/sub/broccoli-seeds-calabrese-vs-sprouting) before you fill a tray. Jar seed does not belong in this calendar. Peter F. checked the listings and public UK sources. A qualifying purchase can earn a commission at no extra cost to you.

How to sow broccoli seeds depends on the packet. A generic March date is how people get bolted calabrese, or a spear plant in a bed wanted for September.

Our top picks

Mr Fothergill's Mr Fothergill's Early Purple

Best overall

Mr Fothergill's Mr Fothergill's Early Purple
7.6/10about £4.09
View offer
Mr Fothergill's Mr Fothergill's Green Calabrese

Best value

Mr Fothergill's Mr Fothergill's Green Calabrese
6.8/10about £2.39
View offer
Mr Fothergill's Mr Fothergill's Covina

Alternative

Mr Fothergill's Mr Fothergill's Covina
3.4/10about £3.49
View offer
On this page
  1. 1.Sow the crop you actually bought
  2. 2.Depth, modules, and water
  3. 3.Spacing and netting
  4. 4.When the seed fails to come up

Sow the crop you actually bought

Early Purple says March to May, then a February to May harvest: purple sprouting sown in spring to stand through winter. Green Calabrese uses the same sowing months and a September to November head. Covina is the later calabrese: indoors February to April, or outdoors March to June, transplant at about 10 cm, and cut from June to November. If the packet and a general webpage disagree, follow the named packet. Garden Organic's later outdoor window is a second opinion, not a reason to drop Early Purple's March start. The RHS warns that a check in warm weather makes calabrese bolt, so many people sow it in the final position after April. Raab is the short contrast: February to September, about 60 days, thinned to 25 cm. It is Brassica rapa. Do not give it 60 cm spacing. Which foil you hold is on the buying guide.

Depth, modules, and water

Use the depth the listing prints. Early Purple is 1.5 cm outdoors and 0.5 cm in trays. Raab is 1.5 cm. Green Calabrese and Covina state none. The RHS module method is a dibber about 2 cm, one seed per cell. Garden Organic mentions about 0.5 cm in trays. Do not average those figures: they belong to different sources. Sprouting broccoli, on the RHS account, germinates within about two weeks without extra heat. Keep compost moist, not pooled. Label the tray. Early Purple and Green Calabrese look the same as seedlings and need opposite futures.
Mr Fothergill's Mr Fothergill's Early Purple

Testsieger

Mr Fothergill's Mr Fothergill's Early Purple
7.6/10about £4.09
View offer

Spacing and netting

Early Purple says transplant about 60 cm apart both ways once seedlings are about 10 cm tall. The RHS range for sprouting broccoli is about 60 to 80 cm, and a winter plant can stand for eight months or more. Garden Organic uses 45 cm in one guide. For this packet, use the 60 cm on the listing. Calabrese is tighter: Kings Seeds talks about 45 cm, and the RHS calabrese guide is about 30 to 45 cm. Covina prints no distance, so use that calabrese range, not the spear spacing. Raab's listing says 25 cm. No packet here mentions mesh. The RHS cabbage root fly page describes fine insect mesh all season, or collars about 8 to 15 cm, so flies from last year's brassicas do not emerge under the cover. Put it on when you plant. Pigeons shred bare leaves. Clubroot stays in the soil. A new packet does not clean it. Choose the packet on the best broccoli seeds page.

When the seed fails to come up

Two short UK reviews cannot prove a germination rate. Green Calabrese has one note that every seed sown came up, inside 19 ratings. Early Purple's two texts never reach a harvest. Covina and Raab have none. A bare tray after a fortnight, kept moist, is a reason to check the packet date. A non-UK Batlle note about a short count is not your Early Purple tray. Do not tip a sprouting bag into the row. If roots look clubbed, stop replanting brassicas there. If you are ill after eating sprouts, that is NHS territory. Bolting calabrese in a hot June, in the RHS account, is a check in growth: water, transplant size, and sowing in the final spot after April.

Common questions

When do I sow broccoli in the UK?
Use the packet. Early Purple and Green Calabrese both say March to May, then spears from February to May or a head from September to November. Covina adds indoor sowing from February and outdoor sowing through June. Raab runs February to September.
How deep do broccoli seeds go?
Early Purple is 1.5 cm outdoors and 0.5 cm indoors. Raab is 1.5 cm. Green Calabrese and Covina print no depth. The RHS module dibber is about 2 cm. Garden Organic mentions about 0.5 cm in trays. Follow the packet when it gives a number.
How far apart are purple sprouting plants?
The Early Purple listing says about 60 cm both ways, once plants are about 10 cm tall. The RHS range is about 60 to 80 cm. For this packet, use 60 cm. Calabrese is about 30 to 45 cm, and raab is 25 cm on its own listing.
Why did the calabrese bolt?
The RHS links bolting to a check in warm weather, including transplant shock. Sowing calabrese where it will crop, after April, avoids that shift. A dry module on a hot step is the same problem at home.
Do I need netting from the day I plant?
Yes for outdoor brassicas in the UK, even though no packet here mentions it. The RHS describes mesh all season against cabbage root fly, or collars about 8 to 15 cm. The same cover helps with pigeons. Mesh after the damage does not undo the eggs.
Can I sow in modules?
Yes. Early Purple allows indoor trays at 0.5 cm from March to May. The RHS method is one seed per cell, about 2 cm deep, with no extra heat, up in about two weeks. A stalled calabrese transplant in warm weather is a bolting risk.

Related pages

Sprouting broccoli seeds at home

Broccoli seeds

Best broccoli seeds for a jar, head, or winter spears

Broccoli seeds buying guide: which crop is in the foil

Calabrese vs sprouting broccoli: same year or winter

Sources

Public UK sources named below. amazon.co.uk prices, stars and review counts on these twelve listings are from the category snapshot. Page updated 21 October 2026.

  1. RHS: grow your own broccoli (retrieved 21 October 2026)
  2. RHS: grow your own calabrese (retrieved 21 October 2026)
  3. RHS: cabbage root fly (retrieved 21 October 2026)
  4. RHS: club root (retrieved 21 October 2026)
  5. RHS: Brassica rapa Ruvo Group (broccoli raab) (retrieved 21 October 2026)
  6. Seed Marketing Regulations 2011 (retrieved 21 October 2026)
  7. FSA: protecting consumers from STEC (retrieved 21 October 2026)
  8. NI Direct: sprouted seeds safety advice (retrieved 21 October 2026)