Pea · Chiba, Chiba, Japan
When to plant peas in Chiba
Main outdoor window
25 Jan - 15 Feb
The window this page is built around.
Timed from last spring frost
8 March
In Chiba, on your chosen risk.
Ready to pick
21 Mar - 5 Apr
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 Chiba
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 for autumn
9-30 Sep
Counting back 84 days from your first frost so the crop matures in time.
Sow direct
25 Jan - 15 Feb
Six weeks before your last frost.
Harvest
21 Mar - 5 Apr
Peas through the year
Against the frost risk in Chiba
Why these dates
Sow as soon as soil is workable - six weeks before last frost is normal. In mild-winter climates an autumn sowing overwinters and crops six weeks earlier than any spring sowing can.
Established pea plants shrug off -6C. Seedlings tolerate frost easily; it is heat, not cold, that ends the crop.
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. Peas are timed for direct sowing 6 weeks before it, and this page simply resolves those offsets against the frost date computed for Chiba.
The median frost-free season here is 291 days, against 55 to 70 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Chiba
Other vegetables to time
Growing peas in Chiba
When should I plant peas in Chiba?
Aim for 25 Jan - 15 Feb in an average year. If you would rather not gamble on the weather, wait until 13 Feb - 6 Mar - by then frost has finished in nine years out of ten.
When will peas be ready to harvest in Chiba?
Expect to start picking around 21 Mar - 5 Apr, based on 55 to 70 days to maturity from the planting date calculated for this location.
How much frost will peas tolerate?
Established pea plants shrug off -6C. Seedlings tolerate frost easily; it is heat, not cold, that ends the crop.