How to grow Lettuce (Cos, Lobjoit's Green)

Lactuca sativa var. longifolia

🥕 Vegetable 🌱 Grown each year

A tall, crunchy cos lettuce with sweet, dark-green leaves — the one for Caesar salad. Slow to bolt and stands well in summer.

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

When to sow, plant and harvest

JanFebMarAprMayJunJulAugSepOctNovDec

Sow outdoors

Harvest

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

Mid March – mid July · 4 weeks before the last spring frost
Sow Seeds Outdoors
Sow thinly in drills where they are to grow. Sow thinly, barely covered; lettuce will not germinate above 25°C, so sow in the evening in summer.
4–10 days after “Sow Seeds Indoors” · Late March
Check Germination
Seedlings should appear in 4–10 days. If sown outdoors, thin to 30 cm apart when big enough to handle.
65–86 days after “Check Germination” · Late May – mid June
Start Harvesting
Cut whole heads when firm, or pick outer leaves as needed.
14–28 days after “Start Harvesting” · Early June – late June
Sow Another Batch (optional)
Sow a few seeds every three weeks for a steady supply.
30–60 days after “Sow Another Batch” · Early July – early August
Finish and Clear
Clear the remains to the compost heap once cropping ends.