Stock · Hamhŭng, South Hamgyong, North Korea
When to sow stocks in Hamhŭng
Main outdoor window
6-27 Apr
The window this page is built around.
Timed from last spring frost
20 April
In Hamhŭng, on your chosen risk.
Ready to pick
25 Jun - 25 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 Hamhŭng
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 Feb - 16 Mar
Eight weeks before your last frost, under cover or on a windowsill.
Plant out
6-27 Apr
Two weeks before your last frost.
In flower
25 Jun - 25 Jul
Stocks through the year
Against the frost risk in Hamhŭng
Why these dates
Start indoors eight weeks before the last frost and plant out two weeks before it. Stocks need cool nights, below about 15C, for several weeks to initiate flower spikes, so early planting is not optional - a late-planted stock grows into a leafy plant that never blooms.
Hardy to about -8C. In zone 8 and warmer the sensible approach is autumn planting for late-winter flowers, and in hot climates it is a winter crop only.
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. Stocks are timed from 8 weeks before that frost for an indoor start, with planting out 2 weeks before it, and this page simply resolves those offsets against the frost date computed for Hamhŭng.
Hardiness is not the obstacle here. Hamhŭng is zone 6a, 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 185 days, against 80 to 110 days to first flower for this crop counted from planting out. That margin is what decides whether a late sowing is worth attempting.
Also in Hamhŭng
Other flowers to time
Growing stocks in Hamhŭng
When should I plant stocks in Hamhŭng?
Aim for 6-27 Apr in an average year. If you would rather not gamble on the weather, wait until 12 Apr - 3 May - by then frost has finished in nine years out of ten.
When will stocks be ready to harvest in Hamhŭng?
Expect to start picking around 25 Jun - 25 Jul, based on 80 to 110 days to maturity from the planting date calculated for this location.
How much frost will stocks tolerate?
Hardy to about -8C. In zone 8 and warmer the sensible approach is autumn planting for late-winter flowers, and in hot climates it is a winter crop only.