Kale · Durham, North Carolina, United States
When to plant kale in Durham
Main outdoor window
15 Mar - 5 Apr
The window this page is built around.
Timed from last spring frost
29 March
In Durham, on your chosen risk.
Ready to pick
9-29 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 Durham
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
15 Feb - 8 Mar
Six weeks before your last frost, under cover or on a windowsill.
Sow for overwintering
21 Jul - 11 Aug
Counting back 89 days from your first frost so the crop matures in time.
Sow direct
15 Mar - 5 Apr
Two weeks before your last frost.
Plant out
15 Mar - 5 Apr
Two weeks before your last frost.
Harvest
9-29 May
Kale through the year
Against the frost risk in Durham
Why these dates
Spring sowings feed you through summer; the sowing made twelve weeks before first frost is the one that carries you through winter.
Survives -12C and sweetens markedly below freezing as starches convert to sugars. Frost is a feature of this crop, not a threat.
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. Kale are timed from 6 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 Durham.
The median frost-free season here is 224 days, against 55 to 75 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Durham
Other vegetables to time
Growing kale in Durham
When should I plant kale in Durham?
Aim for 15 Mar - 5 Apr in an average year. If you would rather not gamble on the weather, wait until 29 Mar - 19 Apr - by then frost has finished in nine years out of ten.
When will kale be ready to harvest in Durham?
Expect to start picking around 9-29 May, based on 55 to 75 days to maturity from the planting date calculated for this location.
How much frost will kale tolerate?
Survives -12C and sweetens markedly below freezing as starches convert to sugars. Frost is a feature of this crop, not a threat.