Grape hyacinth · Kanggye, Chagang, North Korea
When to sow grape hyacinths in Kanggye
Main outdoor window
22 Aug - 5 Sep
The window this page is built around.
Timed from last spring frost
8 May
In Kanggye, on your chosen risk.
Ready to pick
1 Mar - 30 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 Kanggye
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 bulbs
22 Aug - 5 Sep
Four to six weeks before your first frost, so roots form before the ground cools.
In flower
1 Mar - 30 Apr
Grape hyacinths through the year
Against the frost risk in Kanggye
Why these dates
Plant in early autumn, 8cm deep. A quirk worth expecting: the leaves appear in autumn, months before the flowers, and look untidy all winter. That is normal and not a sign of a bulb planted at the wrong time.
Hardy to -30C, with winter foliage that shrugs off hard frost. Naturalises readily and needs no cold-winter chill beyond what any temperate zone provides.
Grape hyacinths 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 Kanggye instead of forwards from its start.
Hardiness is not the obstacle here. Kanggye is zone 4b, 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 148 days, against 130 to 180 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Kanggye
Other flowers to time
Growing grape hyacinths in Kanggye
When should I plant grape hyacinths in Kanggye?
Aim for 22 Aug - 5 Sep in an average year. If you would rather not gamble on the weather, wait until 15-29 Aug - by then frost has finished in nine years out of ten.
When will grape hyacinths be ready to harvest in Kanggye?
Expect to start picking around 1 Mar - 30 Apr, based on 130 to 180 days to maturity from the planting date calculated for this location.
How much frost will grape hyacinths tolerate?
Hardy to -30C, with winter foliage that shrugs off hard frost. Naturalises readily and needs no cold-winter chill beyond what any temperate zone provides.