Butterhead lettuce · Goyang-si, Gyeonggi-do, South Korea
When to plant butterhead lettuce in Goyang-si
Main outdoor window
13-27 Mar
The window this page is built around.
Timed from last spring frost
3 April
In Goyang-si, 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 Goyang-si
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
20 Feb - 6 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
13-27 Mar
Three weeks before your last frost.
Sow direct
20 Mar - 3 Apr
Two weeks before your last frost.
Harvest
1 May - 31 Oct
Butterhead lettuce through the year
Against the frost risk in Goyang-si
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 Goyang-si.
The median frost-free season here is 223 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.
Nearby
Butterhead lettuce in places close by
Also in Goyang-si
Other vegetables to time
Growing butterhead lettuce in Goyang-si
When should I plant butterhead lettuce in Goyang-si?
Aim for 13-27 Mar in an average year. If you would rather not gamble on the weather, wait until 22 Mar - 5 Apr - by then frost has finished in nine years out of ten.
When will butterhead lettuce be ready to harvest in Goyang-si?
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.