Sweet pea · Richmond, British Columbia, Canada
When to sow sweet peas in Richmond
Main outdoor window
14 Jan - 4 Feb
The window this page is built around.
Timed from last spring frost
25 February
In Richmond, on your chosen risk.
Ready to pick
14 Apr - 4 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 Richmond
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
17 Dec - 7 Jan
Ten weeks before your last frost, under cover or on a windowsill.
Sow for overwintering
13 Jul - 3 Aug
Counting back 124 days from your first frost so the crop matures in time.
Sow direct
14 Jan - 4 Feb
Six weeks before your last frost.
Plant out
28 Jan - 18 Feb
Four weeks before your last frost.
In flower
14 Apr - 4 May
Sweet peas through the year
Against the frost risk in Richmond
Why these dates
Sow in autumn and overwinter in a cold frame in zone 6 and warmer, or start ten weeks before last frost. Pinch at four true leaves.
Young plants take -8C and benefit from the cold. This is a flower where autumn sowing genuinely doubles the season.
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. Sweet peas are timed from 10 weeks before that frost for an indoor start, with planting out 4 weeks before it, and this page simply resolves those offsets against the frost date computed for Richmond.
The median frost-free season here is 283 days, against 90 to 110 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Growing sweet peas in Richmond
When should I plant sweet peas in Richmond?
Aim for 14 Jan - 4 Feb in an average year. If you would rather not gamble on the weather, wait until 29 Jan - 19 Feb - by then frost has finished in nine years out of ten.
When will sweet peas be ready to harvest in Richmond?
Expect to start picking around 14 Apr - 4 May, based on 90 to 110 days to maturity from the planting date calculated for this location.
How much frost will sweet peas tolerate?
Young plants take -8C and benefit from the cold. This is a flower where autumn sowing genuinely doubles the season.