Safe to Plant

Butterhead lettuce · Ziyang, Sichuan, China

When to plant butterhead lettuce in Ziyang

Main outdoor window

17-31 Jan

The window this page is built around.

Timed from last spring frost

7 February

In Ziyang, 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 Ziyang

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

26 Dec - 10 Jan

Six weeks before your last frost, under cover or on a windowsill.

Sow for autumn

13 Sep - 4 Oct

Counting back 74 days from your first frost so the crop matures in time.

Sow direct

17-31 Jan

Three weeks before your last frost.

Sow direct

24 Jan - 7 Feb

Two weeks before your last frost.

Harvest

1 May - 31 Oct

Sow in succession. A single sowing gives you a single glut. Sow a short row every 10 days through the window above and you get a steady supply instead.
Frost tolerance
Half-hardy
Damaged below
-3°C (26.6°F)
Days to maturity
45–60
Min soil temp
4.5°C (40.1°F)
Spacing
25 cm
Sowing depth
6 mm (0.2 in)
Sun
Partial

Butterhead lettuce through the year

Against the frost risk in Ziyang

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Frost risk Start indoors Autumn sowing Sow direct Plant out Harvest Today

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 Ziyang.

The median frost-free season here is 313 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.

See every crop timed for Ziyang →

Growing butterhead lettuce in Ziyang

When should I plant butterhead lettuce in Ziyang?

Aim for 17-31 Jan in an average year. If you would rather not gamble on the weather, wait until 30 Jan - 13 Feb - by then frost has finished in nine years out of ten.

When will butterhead lettuce be ready to harvest in Ziyang?

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.