Water chestnut · Arequipa, Arequipa, Peru
When to plant water chestnuts in Arequipa
Main outdoor window
2-23 Sep
The window this page is built around.
Timed from last spring frost
19 August
In Arequipa, on your chosen risk.
Ready to pick
31 Mar - 30 Jun
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 Arequipa
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 corms
2-23 Sep
Two weeks after your last frost.
Harvest
31 Mar - 30 Jun
Water chestnuts through the year
Against the frost risk in Arequipa
Why these dates
Plant corms two weeks after the last frost into 5cm of standing water. Drain in autumn once the tops yellow, then dig the corms out of the drying mud.
Top growth is killed at 0C, which is the signal to drain and harvest. Corms need around 200 frost-free days to size up.
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. Water chestnuts are timed with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Arequipa.
The median frost-free season here is 288 days, against 180 to 220 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Arequipa
Other vegetables to time
Growing water chestnuts in Arequipa
When should I plant water chestnuts in Arequipa?
Aim for 2-23 Sep in an average year. If you would rather not gamble on the weather, wait until 23 Sep - 14 Oct - by then frost has finished in nine years out of ten.
When will water chestnuts be ready to harvest in Arequipa?
Expect to start picking around 31 Mar - 30 Jun, based on 180 to 220 days to maturity from the planting date calculated for this location.
How much frost will water chestnuts tolerate?
Top growth is killed at 0C, which is the signal to drain and harvest. Corms need around 200 frost-free days to size up.