Tomato · Chengdu, Sichuan, China
When to plant tomatoes in Chengdu
Main outdoor window
28 Feb - 21 Mar
The window this page is built around.
Timed from last spring frost
14 February
In Chengdu, on your chosen risk.
Ready to pick
29 Apr - 24 May
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 Chengdu
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
3-24 Jan
Six weeks before your last frost, under cover or on a windowsill.
Plant out
28 Feb - 21 Mar
Two weeks after your last frost.
Harvest
29 Apr - 24 May
Tomatoes through the year
Against the frost risk in Chengdu
Why these dates
Six weeks of indoor growing produces a stocky transplant with a first flower truss forming. Starting earlier than eight weeks usually backfires: the plant becomes leggy and root-bound, and gains nothing on a plant sown later.
Tomato foliage is damaged at 0C and killed outright at about -1C. There is no recovery from a frosted plant, so the transplant date is the single most consequential decision in the tomato year.
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. Tomatoes are timed from 6 weeks before that frost for an indoor start, with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Chengdu.
The median frost-free season here is 300 days, against 60 to 85 days to maturity for this crop counted from planting out. That margin is what decides whether a late sowing is worth attempting.
Also in Chengdu
Other vegetables to time
Growing tomatoes in Chengdu
When should I plant tomatoes in Chengdu?
Aim for 28 Feb - 21 Mar in an average year. If you would rather not gamble on the weather, wait until 20 Mar - 10 Apr - by then frost has finished in nine years out of ten.
When will tomatoes be ready to harvest in Chengdu?
Expect to start picking around 29 Apr - 24 May, based on 60 to 85 days to maturity from the planting date calculated for this location.
How much frost will tomatoes tolerate?
Tomato foliage is damaged at 0C and killed outright at about -1C. There is no recovery from a frosted plant, so the transplant date is the single most consequential decision in the tomato year.