Mashua · Philadelphia, Pennsylvania, United States
When to plant mashua in Philadelphia
Main outdoor window
14 Apr - 12 May
The window this page is built around.
Timed from last spring frost
14 April
In Philadelphia, 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 Philadelphia
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
14 Apr - 12 May
Around your last frost.
Harvest
1 Nov - 31 Dec
Mashua through the year
Against the frost risk in Philadelphia
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 Philadelphia.
Philadelphia sits in zone 7a, 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 202 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 Philadelphia
Other vegetables to time
Growing mashua in Philadelphia
When should I plant mashua in Philadelphia?
Aim for 14 Apr - 12 May in an average year. If you would rather not gamble on the weather, wait until 23 Apr - 21 May - by then frost has finished in nine years out of ten.
When will mashua be ready to harvest in Philadelphia?
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.