Vegetable · Asteraceae
When to plant iceberg lettuce
Needs three or four more weeks than any other lettuce and a steady supply of water throughout, which is the whole difficulty with it.
Start seed indoors
6 weeks before
Counted from your last spring frost.
Plant out
2 weeks before
Counted from your last spring frost.
Sow direct
3 weeks before
Counted from your last spring frost.
Those weeks become real dates once you name a place.
Timing, in frost-relative terms
Seed packets rarely give calendar dates, because a date that suits one latitude is wrong at another. They give offsets from the last spring frost instead, and those offsets are what make iceberg lettuce plantable anywhere.
- Start seed indoors 6 weeks before the last frost.
- Plant out 2 weeks before the last frost.
- Sow direct 3 weeks before the last frost.
- Expect 70–85 days to maturity, counted from sowing.
- Sow again every 14 days for a continuous supply.
Getting the timing right
Start indoors six weeks before the last frost and plant out two weeks before. A check to growth at any point gives you a loose head rather than a dense one.
Frost tolerance
Takes around -3C. The long season means a late sowing can be caught by the first autumn frost before it has hearted.
Classified as half-hardy, with damage expected below -3°C (26.6°F)26.6°F (-3°C).