Safe to Plant

Pak choi · Hŭngnam, South Hamgyong, North Korea

When to plant pak choi in Hŭngnam

Main outdoor window

6-20 Apr

The window this page is built around.

Timed from last spring frost

20 April

In Hŭngnam, on your chosen risk.

Ready to pick

16-31 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 Hŭngnam

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

23 Mar - 6 Apr

Four weeks before your last frost, under cover or on a windowsill.

Sow for autumn

23 Jul - 13 Aug

Counting back 69 days from your first frost so the crop matures in time.

Sow direct

6-20 Apr

Two weeks before your last frost.

Plant out

13-27 Apr

One week before your last frost.

Harvest

16-31 May

Sow in succession. A single sowing gives you a single glut. Sow a short row every 14 days through the window above and you get a steady supply instead.
Frost tolerance
Half-hardy
Damaged below
-4°C (24.8°F)
Days to maturity
40–55
Min soil temp
10°C (50°F)
Spacing
20 cm
Sowing depth
12 mm (0.5 in)
Sun
Partial

Pak choi through the year

Against the frost risk in Hŭngnam

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

Frost risk Start indoors Autumn sowing Sow direct Plant out Harvest Today

Why these dates

The autumn sowing is the dependable one. Spring sowings bolt readily unless made very early or grown under cover.

Handles a few degrees of frost. A hard freeze destroys the succulent midribs.

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. Pak choi are timed from 4 weeks before that frost for an indoor start, with planting out 1 weeks before it, and this page simply resolves those offsets against the frost date computed for Hŭngnam.

The median frost-free season here is 185 days, against 40 to 55 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 Hŭngnam →

Growing pak choi in Hŭngnam

When should I plant pak choi in Hŭngnam?

Aim for 6-20 Apr in an average year. If you would rather not gamble on the weather, wait until 12-26 Apr - by then frost has finished in nine years out of ten.

When will pak choi be ready to harvest in Hŭngnam?

Expect to start picking around 16-31 May, based on 40 to 55 days to maturity from the planting date calculated for this location.

How much frost will pak choi tolerate?

Handles a few degrees of frost. A hard freeze destroys the succulent midribs.