Butterhead lettuce · Mexico City, Mexico City, Mexico
When to plant butterhead lettuce in Mexico City
Main outdoor window
19 Jan - 2 Feb
The window this page is built around.
Timed from last spring frost
9 February
In Mexico 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 Mexico 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
29 Dec - 12 Jan
Six weeks before your last frost, under cover or on a windowsill.
Sow for autumn
14 Aug - 4 Sep
Counting back 74 days from your first frost so the crop matures in time.
Sow direct
19 Jan - 2 Feb
Three weeks before your last frost.
Sow direct
26 Jan - 9 Feb
Two weeks before your last frost.
Harvest
1 May - 31 Oct
Butterhead lettuce through the year
Against the frost risk in Mexico 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 Mexico City.
The median frost-free season here is 281 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 Mexico City
Other vegetables to time
Growing butterhead lettuce in Mexico City
When should I plant butterhead lettuce in Mexico City?
Aim for 19 Jan - 2 Feb in an average year. If you would rather not gamble on the weather, wait until 13-27 Feb - by then frost has finished in nine years out of ten.
When will butterhead lettuce be ready to harvest in Mexico 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.