Kale · Olathe, Kansas, United States
When to plant kale in Olathe
Main outdoor window
31 Mar - 21 Apr
The window this page is built around.
Timed from last spring frost
14 April
In Olathe, on your chosen risk.
Ready to pick
25 May - 14 Jun
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 Olathe
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
3-24 Mar
Six weeks before your last frost, under cover or on a windowsill.
Sow for overwintering
8-29 Jul
Counting back 89 days from your first frost so the crop matures in time.
Sow direct
31 Mar - 21 Apr
Two weeks before your last frost.
Plant out
31 Mar - 21 Apr
Two weeks before your last frost.
Harvest
25 May - 14 Jun
Kale through the year
Against the frost risk in Olathe
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 Olathe.
The median frost-free season here is 195 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 Olathe
Other vegetables to time
Growing kale in Olathe
When should I plant kale in Olathe?
Aim for 31 Mar - 21 Apr in an average year. If you would rather not gamble on the weather, wait until 8-29 Apr - by then frost has finished in nine years out of ten.
When will kale be ready to harvest in Olathe?
Expect to start picking around 25 May - 14 Jun, 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.