Purple sprouting broccoli · Edmonton, Alberta, Canada
When to plant purple sprouting broccoli in Edmonton
Main outdoor window
22 Jul - 19 Aug
The window this page is built around.
Timed from last spring frost
13 May
In Edmonton, on your chosen risk.
Ready to pick
1 Feb - 30 Apr
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 Edmonton
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.
Sow direct
22 Jul - 19 Aug
Ten weeks after your last frost.
Harvest
1 Feb - 30 Apr
Purple sprouting broccoli through the year
Against the frost risk in Edmonton
Why these dates
Sow around ten weeks after the last spring frost, plant out into firm ground, and leave it standing all winter. Spears come in late winter and early spring, months after sowing.
Hardy to roughly -12C and needs a cold period to initiate spears at all, so a mild winter can leave the plant leafy and unproductive.
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. Purple sprouting broccoli are timed for direct sowing 10 weeks after it, and this page simply resolves those offsets against the frost date computed for Edmonton.
The median frost-free season here is 137 days, against 220 to 300 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Edmonton
Other vegetables to time
Growing purple sprouting broccoli in Edmonton
When should I plant purple sprouting broccoli in Edmonton?
Aim for 22 Jul - 19 Aug in an average year. If you would rather not gamble on the weather, wait until 31 Jul - 28 Aug - by then frost has finished in nine years out of ten.
When will purple sprouting broccoli be ready to harvest in Edmonton?
Expect to start picking around 1 Feb - 30 Apr, based on 220 to 300 days to maturity from the planting date calculated for this location.
How much frost will purple sprouting broccoli tolerate?
Hardy to roughly -12C and needs a cold period to initiate spears at all, so a mild winter can leave the plant leafy and unproductive.