When to sow calendulas in Cần Thơ

Why these dates

Sow direct three weeks before the last frost, or start indoors six weeks before it for the earliest flowers. Sow again every three weeks until midsummer for continuous bloom. In mild winters an autumn sowing overwinters as a small rosette and flowers a month earlier than anything sown in spring.

Takes light frost to about -8C without stopping, and often flowers straight through a mild winter in zone 9 and warmer. Heat is the greater enemy: it sulks and mildews above 30C and is best treated as a spring and autumn flower in hot climates.

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. Calendulas are timed from 6 weeks before that frost for an indoor start, with planting out 2 weeks before it, and this page simply resolves those offsets against the frost date computed for Cần Thơ.

Cần Thơ sits in zone 13a, which is milder than this crop wants, and a winter that never really arrives is its own problem. The dates below still describe the right time of year; the open question is survival rather than timing.

See every crop timed for Cần Thơ →