Safe to Plant

Crocus · Pyongyang, Pyongyang, North Korea

When to sow crocuses in Pyongyang

Main outdoor window

19 Sep - 3 Oct

The window this page is built around.

Timed from last spring frost

10 April

In Pyongyang, on your chosen risk.

Ready to pick

1 Feb - 31 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 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.

Plant the corms

19 Sep - 3 Oct

Four to six weeks before your first frost, so roots form before the ground cools.

In flower

1 Feb - 31 Mar

Frost tolerance
Very-hardy
Damaged below
-30°C (-22°F)
Days to flowering
120–170
Hardy to
Zone 3a–8a
Spacing
8 cm
Sowing depth
80 mm (3.1 in)
Sun
Full

Crocuses through the year

Against the frost risk in Pyongyang

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

Frost risk Plant Harvest Today

Why these dates

Plant in early autumn, six to eight weeks before the first frost, 8cm deep. Naturalising in grass is the best use of them: they flower and set seed before the first cut of the season is due, so the lawn can be left uncut until the leaves yellow in late spring.

Hardy to -30C and among the most frost-indifferent flowers grown - blooms freeze solid overnight and reopen the same morning. Needs a cold winter to flower well and fails in zone 9 and warmer.

Crocuses are anchored to the first autumn frost rather than the last spring one, so the planting window on this page counts backwards from the end of the season in Pyongyang instead of forwards from its start.

Hardiness is not the obstacle here. Pyongyang is zone 7a, comfortably inside the range this crop is rated for, so an established plant should come through an average winter without protection.

The median frost-free season here is 204 days, against 120 to 170 days to first flower 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 crocuses in Pyongyang

When should I plant crocuses in Pyongyang?

Aim for 19 Sep - 3 Oct in an average year. If you would rather not gamble on the weather, wait until 7-21 Sep - by then frost has finished in nine years out of ten.

When will crocuses be ready to harvest in Pyongyang?

Expect to start picking around 1 Feb - 31 Mar, based on 120 to 170 days to maturity from the planting date calculated for this location.

How much frost will crocuses tolerate?

Hardy to -30C and among the most frost-indifferent flowers grown - blooms freeze solid overnight and reopen the same morning. Needs a cold winter to flower well and fails in zone 9 and warmer.