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← How to grow broccoli
Planting Calendar · Zone 4A

When to plant broccoli in zone 4a

In USDA zone 4a, start broccoli seeds indoors around Mar 26, transplant outdoors Apr 16, and harvest from Jul 5.

Growing SeasonZone 4a
Last frost ~May 7First frost ~Oct 13Today
Start indoorsTransplant / sowHarvestFrost risk
MARAPRMAYJUNJULAUG
Start indoors Mar 26 · Transplant Apr 16 · First harvest Jul 5 · Wrap by Aug 2
Last spring frostMay 7
Start seeds indoorsMar 26
Transplant outApr 16
First harvestJul 5
Last harvestAug 2
Fall succession sowJul 14
First fall frostOct 13

Why these dates work in zone 4a

Zone 4a's last spring frost averages May 7 and first fall frost Oct 13 — about 159 frost-free days. Broccoli tolerates light frost, so you can set plants out ahead of the last-frost date and keep harvesting into the cooler fall. Starting seeds indoors 6 weeks ahead gives strong transplants ready the moment the soil warms. There's also room for a fall succession sowing around Jul 14 for a second harvest before frost.

Common questions

How long does broccoli take to grow in zone 4a?

Broccoli matures in about 80–100 days from transplanting. In zone 4a that means setting plants out around Apr 16 and first picking around Jul 5.

Will broccoli survive frost in zone 4a?

Yes — broccoli tolerates light frost. In zone 4a you can set plants out a little before the last frost (around May 7) and keep harvesting past the first fall frost (around Oct 13).

Can I plant a second crop of broccoli in zone 4a?

Yes — in zone 4a there's time for a fall sowing around Jul 14 for a second harvest before frost.

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