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Planting Calendar · Zone 3A

When to plant sunflower in zone 3a

In USDA zone 3a, sow sunflower around May 30, and harvest from Jul 29.

We don’t publish a planting calendar for zone 3a, because every date on one would be counted from a last-frost date this zone doesn’t reliably have. Sunflower takes about 60–100 days from sowing to first picking, and that part holds anywhere. For real dates, tell us where you are below and Garzed reads ten years of weather at your own coordinates.

Why these dates work in zone 3a

Zone 3a's last spring frost averages May 30 and first fall frost Sep 10 — about 103 frost-free days. Sunflower is frost-sensitive, so the around last frost timing builds in a safety margin against a late cold snap — setting plants out too early risks losing them to frost. One caveat: we haven't yet checked zone 3a against the weather archive, so those frost dates are an inherited estimate rather than a measurement. Give Garzed your location and it works from that location's own ten-year record instead.

Common questions

How long does sunflower take to grow in zone 3a?

Sunflower matures in about 60–100 days from sowing. In zone 3a that means sowing around May 30 and first picking around Jul 29.

Will sunflower survive frost in zone 3a?

No — sunflower is frost-sensitive. In zone 3a, wait until after the last frost (around May 30) to plant, and harvest before the first fall frost (around Sep 10).

For soil, spacing, pests and companion planting, see the full sunflower growing guide →