Swiss chard · Olathe, Kansas, United States
When to plant swiss chard 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
20-30 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 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
10-31 Mar
Five weeks before your last frost, under cover or on a windowsill.
Sow for overwintering
23 Jul - 13 Aug
Counting back 74 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
7-28 Apr
One week before your last frost.
Harvest
20-30 May
Swiss chard through the year
Against the frost risk in Olathe
Why these dates
One spring sowing usually lasts until hard frost. In mild climates it overwinters and produces an early spring flush before bolting.
Takes -5C without protection. Under a cloche it will hold through much colder weather and resume growth in late winter.
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. Swiss chard are timed from 5 weeks before that frost for an indoor start, with planting out 1 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 50 to 60 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 swiss chard in Olathe
When should I plant swiss chard 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 swiss chard be ready to harvest in Olathe?
Expect to start picking around 20-30 May, based on 50 to 60 days to maturity from the planting date calculated for this location.
How much frost will swiss chard tolerate?
Takes -5C without protection. Under a cloche it will hold through much colder weather and resume growth in late winter.