Radish · Tokyo, Tokyo, Japan
When to plant radishes in Tokyo
Main outdoor window
8-15 Feb
The window this page is built around.
Timed from last spring frost
8 March
In Tokyo, on your chosen risk.
Ready to pick
2-10 Mar
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 for autumn
19 Oct - 9 Nov
Counting back 44 days from your first frost so the crop matures in time.
Sow direct
8-15 Feb
Four weeks before your last frost.
Harvest
2-10 Mar
Radishes through the year
Against the frost risk in Tokyo
Why these dates
Sow every week in spring and autumn. Summer sowings turn woody and hot - stop when daytime temperatures pass 25C and resume in late summer.
Handles -6C easily and is often the first and last thing harvested in the 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. Radishes are timed for direct sowing 4 weeks before 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 22 to 30 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 radishes in Tokyo
When should I plant radishes in Tokyo?
Aim for 8-15 Feb in an average year. If you would rather not gamble on the weather, wait until 27 Feb - 6 Mar - by then frost has finished in nine years out of ten.
When will radishes be ready to harvest in Tokyo?
Expect to start picking around 2-10 Mar, based on 22 to 30 days to maturity from the planting date calculated for this location.
How much frost will radishes tolerate?
Handles -6C easily and is often the first and last thing harvested in the year.