Delphinium · Pyongyang, Pyongyang, North Korea
When to sow delphiniums in Pyongyang
Main outdoor window
24 Apr - 22 May
The window this page is built around.
Timed from last spring frost
10 April
In Pyongyang, on your chosen risk.
Ready to pick
1 Jun - 31 Jul
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.
Start indoors
19 Jun - 17 Jul
Ten weeks before your last frost, under cover or on a windowsill.
Plant out
24 Apr - 22 May
Two weeks after your last frost.
In flower
1 Jun - 31 Jul
Delphiniums through the year
Against the frost risk in Pyongyang
Why these dates
Plant out in spring after the last frost, or in early autumn where winters are mild. Stake early, before the spikes are half grown - a delphinium staked after it leans never straightens. Cut spent spikes to the base for a lighter second flowering in early autumn.
Hardy to -30C when dormant, but dislikes hot humid summers more than cold winters and is genuinely difficult above zone 7. Emerging shoots are a favourite of slugs and are checked by hard late frosts.
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. Delphiniums are timed from 10 weeks before that frost for an indoor start, with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Pyongyang.
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.
Do not expect a crop in the first year. A plant set out now should give its first worthwhile pick around year 1, and will then produce every year after that, which is what makes the planting decision worth getting right the first time.
Also in Pyongyang
Other flowers to time
Growing delphiniums in Pyongyang
When should I plant delphiniums in Pyongyang?
Aim for 24 Apr - 22 May in an average year. If you would rather not gamble on the weather, wait until 5 May - 2 Jun - by then frost has finished in nine years out of ten.
When will delphiniums be ready to harvest in Pyongyang?
Expect to start picking around 1 Jun - 31 Jul, based on 130 to 160 days to maturity from the planting date calculated for this location.
How much frost will delphiniums tolerate?
Hardy to -30C when dormant, but dislikes hot humid summers more than cold winters and is genuinely difficult above zone 7. Emerging shoots are a favourite of slugs and are checked by hard late frosts.