When to Plant Broccoli

Planting time for broccoli is set by your frost dates, not by the calendar month. Start seeds indoors about 6 weeks before your last spring frost, then transplant once the soil has warmed. From there it takes roughly 65 days to the first harvest. Broccoli is a half-hardy crop, and it keeps going about 21 days past a light frost, which is what makes a fall crop worth planting. Pick your zone below for exact dates, or find your zone by ZIP if you are not sure which one you are in.

Fall broccoli avoids the spring problem of heads buttoning up when temperatures spike. Start transplants indoors in midsummer rather than direct sowing into hot soil.

Fall dates are counted backward from your first frost, not forward from a sowing date. Take the 65 days broccoli needs, add about two weeks because growth slows once days shorten after the equinox, then subtract the roughly 21 days broccoli keeps going once light frost arrives. That is 58 days before your first frost. The coldest zone where this still works on the averages is Zone 3a.

For the whole-garden version of this arithmetic, see the fall planting calendar by zone, and how to read and stretch your first frost date.

Broccoli grows well next to onions, beets and cilantro. Cilantro left to flower draws the parasitic wasps and hoverflies that prey on cabbage worms. The full grid for all 24 crops is in the companion planting chart.