Butterhead lettuce · Zhu Cheng City, Shandong, China
When to plant butterhead lettuce in Zhu Cheng City
Main outdoor window
10-24 Mar
The window this page is built around.
Timed from last spring frost
31 March
In Zhu Cheng City, on your chosen risk.
Ready to pick
1 May - 31 Oct
If you plant at the start of the window.
The average last frost. Half of all years are later than this.
Step by step in Zhu Cheng City
Each window is a range, not a single day. Earlier in the range buys you a longer season; later in it buys you a safer one.
Start indoors
17 Feb - 3 Mar
Six weeks before your last frost, under cover or on a windowsill.
Sow for autumn
9-30 Aug
Counting back 74 days from your first frost so the crop matures in time.
Sow direct
10-24 Mar
Three weeks before your last frost.
Sow direct
17-31 Mar
Two weeks before your last frost.
Harvest
1 May - 31 Oct
Butterhead lettuce through the year
Against the frost risk in Zhu Cheng City
Why these dates
Sow every ten days from six weeks before the last frost, then stop through the hottest weeks and resume eight weeks before the first autumn frost.
Damaged below about -3C. It is heat rather than cold that ends this crop, with seed germinating badly above 25C.
Seed packets and extension guides express timing as weeks either side of the last spring frost, because that is the only reference point that travels. Butterhead lettuce are timed from 6 weeks before that frost for an indoor start, with planting out 2 weeks before it, and this page simply resolves those offsets against the frost date computed for Zhu Cheng City.
The median frost-free season here is 226 days, against 45 to 60 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Zhu Cheng City
Other vegetables to time
Growing butterhead lettuce in Zhu Cheng City
When should I plant butterhead lettuce in Zhu Cheng City?
Aim for 10-24 Mar in an average year. If you would rather not gamble on the weather, wait until 21 Mar - 4 Apr - by then frost has finished in nine years out of ten.
When will butterhead lettuce be ready to harvest in Zhu Cheng City?
Expect to start picking around 1 May - 31 Oct, based on 45 to 60 days to maturity from the planting date calculated for this location.
How much frost will butterhead lettuce tolerate?
Damaged below about -3C. It is heat rather than cold that ends this crop, with seed germinating badly above 25C.