Mashua · Edmonton, Alberta, Canada
When to plant mashua in Edmonton
Main outdoor window
13 May - 10 Jun
The window this page is built around.
Timed from last spring frost
13 May
In Edmonton, on your chosen risk.
Ready to pick
1 Nov - 31 Dec
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.
Plant tubers
13 May - 10 Jun
Around your last frost.
Harvest
1 Nov - 31 Dec
Mashua through the year
Against the frost risk in Edmonton
Why these dates
As for oca: the tops go at about -2C and the crop is lifted afterwards.
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. Mashua are timed with planting out 0 weeks after it, and this page simply resolves those offsets against the frost date computed for Edmonton.
Edmonton sits in zone 4a, which is colder than this crop is rated for, so it will need winter protection or a container that can be moved under cover. The dates below still describe the right time of year; the open question is survival rather than timing.
The median frost-free season here is 137 days, against 180 to 210 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 mashua in Edmonton
When should I plant mashua in Edmonton?
Aim for 13 May - 10 Jun in an average year. If you would rather not gamble on the weather, wait until 22 May - 19 Jun - by then frost has finished in nine years out of ten.
When will mashua be ready to harvest in Edmonton?
Expect to start picking around 1 Nov - 31 Dec, based on 180 to 210 days to maturity from the planting date calculated for this location.
How much frost will mashua tolerate?
As for oca: the tops go at about -2C and the crop is lifted afterwards.