Green bean · Tokyo, Tokyo, Japan
When to plant green beans in Tokyo
Main outdoor window
15-29 Mar
The window this page is built around.
Timed from last spring frost
8 March
In Tokyo, on your chosen risk.
Ready to pick
4-14 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 Tokyo
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.
Sow direct
15-29 Mar
One week after your last frost.
Harvest
4-14 May
Green beans through the year
Against the frost risk in Tokyo
Why these dates
Sow a short row every two weeks from one week after last frost until ten weeks before first frost. Beans crop heavily for a fortnight then decline, so succession matters more than quantity.
Beans are killed by the lightest frost at any stage. They also germinate poorly below 15C, so patience in spring pays.
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. Green beans are timed for direct sowing 1 weeks after it, and this page simply resolves those offsets against the frost date computed for Tokyo.
The median frost-free season here is 291 days, against 50 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 Tokyo
Other vegetables to time
Growing green beans in Tokyo
When should I plant green beans in Tokyo?
Aim for 15-29 Mar in an average year. If you would rather not gamble on the weather, wait until 3-17 Apr - by then frost has finished in nine years out of ten.
When will green beans be ready to harvest in Tokyo?
Expect to start picking around 4-14 May, based on 50 to 60 days to maturity from the planting date calculated for this location.
How much frost will green beans tolerate?
Beans are killed by the lightest frost at any stage. They also germinate poorly below 15C, so patience in spring pays.