When to plant sunflower in zone 5a — planting calendar

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Showing USDA Zone 5A

Growing SeasonZone 5a

Last frost ~May 10First frost ~Oct 1Today

Start indoorsTransplant / sowHarvestFrost risk

APRMAYJUNJULAUG

Sow May 10 · First harvest Jul 9 · Wrap by Aug 6

Last spring frostMay 10

Direct sowMay 10

First harvestJul 9

Last harvestAug 6

First fall frostOct 1

Why these dates work in zone 5a

Zone 5a's last spring frost averages May 10 and first fall frost Oct 1 — about 144 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.

Common questions

How long does sunflower take to grow in zone 5a?

Sunflower matures in about 60–100 days from sowing. In zone 5a that means sowing around May 10 and first picking around Jul 9.

Will sunflower survive frost in zone 5a?

No — sunflower is frost-sensitive. In zone 5a, wait until after the last frost (around May 10) to plant, and harvest before the first fall frost (around Oct 1).

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