How to Grow Lettuce That Never Turns Bitter

Eight steps to steady salad leaves, and the heat and timing mistakes that turn a crop bitter overnight.

The steps

1. Sow in Cool Weather. Spring and autumn are best. Heat turns leaves bitter.
2. Sow Shallow. Barely cover the seed. Light helps it germinate.
3. Give Light Shade. Afternoon shade in summer. Shade delays bolting.
4. Keep Soil Damp. Shallow roots dry out fast. Water little and often.
5. Thin Early. Thin to a hand’s width. Crowding gives small heads.
6. Feed Lightly. Compost is usually enough. Leafy crops want nitrogen.
7. Cut, Don’t Pull. Take outer leaves only. The centre keeps growing.
8. Pull at Bolting. A tall stem means bitter. Pull it and sow again.

Pro tip. Sow a short row every two weeks rather than one long row at once. Lettuce goes from perfect to bitter in a matter of days, so a steady trickle beats a glut you cannot eat in time.