How to grow Collard Greens

Brassica oleracea var. viridis

🥕 Vegetable 🌱 Grown each year

Big, smooth, cabbage-flavoured leaves that crop for months and stand winter cold. A non-heading cabbage — easy and forgiving.

At a glance: Sow early March to mid May, harvest from late June.

When to sow, plant and harvest

JanFebMarAprMayJunJulAugSepOctNovDec

Sow indoors

Plant

Harvest

Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.

Early March – mid May · 6 weeks before the last spring frost
Sow Seeds Indoors
Sow in modules or small pots of seed compost under cover.
5–10 days after “Sow Seeds Indoors” · Early March – mid March
Check Germination
Seedlings should appear in 5–10 days. If sown outdoors, thin to 45 cm apart when big enough to handle.
14–21 days after “Check Germination” · Late March
Pot On Seedlings
Move seedlings into 9 cm pots (or keep in modules) when they have their first true leaves.
Late April · 11 days after the last spring frost
Harden Off
Stand plants outside by day for 7–10 days before planting out.
Early May – early June · 3 weeks after the last spring frost
Plant Out
Plant out 45 cm apart and water in well.
0–3 days after “Plant Out” · Early May
Net Against Pests
Cover with fine insect mesh or netting straight after planting to keep off pigeons, cabbage white caterpillars and flea beetles.
50–71 days after “Plant Out” · Late June – mid July
Start Harvesting
Pick the lower leaves when hand-sized, leaving the top to keep growing.
150–180 days after “Start Harvesting” · Late November – late December
Finish and Clear
Clear the remains to the compost heap once cropping ends.