Safe to Plant

Spring onion · Pyongyang, Pyongyang, North Korea

When to plant spring onions in Pyongyang

Main outdoor window

13-27 Mar

The window this page is built around.

Timed from last spring frost

10 April

In Pyongyang, on your chosen risk.

Ready to pick

7-27 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 Pyongyang

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 overwintering

13 Jul - 3 Aug

Counting back 89 days from your first frost so the crop matures in time.

Sow direct

13-27 Mar

Four weeks before your last frost.

Harvest

7-27 May

Sow in succession. A single sowing gives you a single glut. Sow a short row every 21 days through the window above and you get a steady supply instead.
Frost tolerance
Hardy
Damaged below
-8°C (17.6°F)
Days to maturity
55–75
Min soil temp
5°C (41°F)
Spacing
3 cm
Sowing depth
10 mm (0.4 in)
Sun
Full

Spring onions through the year

Against the frost risk in Pyongyang

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

Frost risk Autumn sowing Sow direct Harvest Today

Why these dates

Sow direct every three weeks from four weeks before the last frost until about ten weeks before the first. An autumn sowing overwinters for a very early spring crop.

Tolerates about -8C. Autumn sowings survive most temperate winters and stand through cold weather without bolting.

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. Spring onions are timed for direct sowing 4 weeks before it, and this page simply resolves those offsets against the frost date computed for Pyongyang.

The median frost-free season here is 204 days, against 55 to 75 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 Pyongyang →

Growing spring onions in Pyongyang

When should I plant spring onions in Pyongyang?

Aim for 13-27 Mar in an average year. If you would rather not gamble on the weather, wait until 24 Mar - 7 Apr - by then frost has finished in nine years out of ten.

When will spring onions be ready to harvest in Pyongyang?

Expect to start picking around 7-27 May, based on 55 to 75 days to maturity from the planting date calculated for this location.

How much frost will spring onions tolerate?

Tolerates about -8C. Autumn sowings survive most temperate winters and stand through cold weather without bolting.