Minnesota planting calendar

When to plant cauliflower in Minnesota — sow, transplant & harvest dates

Minnesota is mostly USDA zone 4b (range 3a-5a). Dates below are derived from cauliflower's frost tolerance and Minnesota's frost window — not generic national averages.

Cauliflower planting timetable for Minnesota

Stage	When in Minnesota	Anchor
Start seeds indoors	early April (April 3)	6 weeks before the last frost (mid-May)
Transplant outside	early May (May 1)	14 days before the last frost (mid-May)
First harvest (estimate)	late July (July 25)	~85 days from transplant

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why Minnesota's climate shifts the cauliflower dates

Minnesota's last spring frost averages mid-May and first fall frost late September, which sets the whole planting clock. Minnesota is one of the coldest states in the contiguous US. Cold-hardy varieties and a compressed season define gardening here. Sow early — cauliflower bolt once daytime temperatures hold above 24 °C, so the earlier they go in, the longer the harvest.

More temperature-sensitive than broccoli — optimal growing range is 15–18 °C (60–65 °F); temperatures above 27 °C (80 °F) cause loose, ricey curds, while a sharp frost below −3 °C (27 °F) can damage developing heads. Start indoors 6–8 weeks before last frost and transplant 2–3 weeks before last frost. Blanch white varieties by tying outer leaves over the curd when it reaches golf-ball size, or choose self-blanching types. Succession planting is difficult in spring in hot climates (zones 7+); fall crops from a midsummer sowing are often more reliable.

Frost-risk note

Don't plant before mid-May — a hard freeze can still set young plants back. In the far north near International Falls (zone 3a) the safe date runs a week or two later.

Regional variation within Minnesota

the far north near International Falls (zone 3a) runs roughly 1-2 weeks behind the state average; the Twin Cities metro and far south (zone 5a) can plant 1-2 weeks earlier.

Minneapolis — USDA zone 5a
Saint Paul — USDA zone 5a
Duluth — USDA zone 4b
Rochester — USDA zone 4b

What else to plant in Minnesota around then

The same early window suits peas, lettuce, spinach, and onion sets.

Quick-grow guide

Sun: Full sun — 6+ hours direct.
Soil temperature for germination: 7–24 °C (45–75 °F).
Spacing: 18–24 inches (45–60 cm) between plants.
Days to harvest: ~85 days from planting out.

Frequently asked questions

When is the best time to plant cauliflower in Minnesota?

In Minnesota (mostly USDA zone 4b), sow cauliflower indoors around early April, transplant outdoors early May (before the last frost, mid-May), and harvest from late July. Cauliflower are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

What USDA zone is Minnesota?

Most of Minnesota sits in USDA hardiness zone 4b, with the state spanning roughly 3a-5a from the far north near International Falls (zone 3a) to the Twin Cities metro and far south (zone 5a). The last spring frost averages mid-May and the first fall frost late September.

Can you grow cauliflower in Minnesota?

Yes. Minnesota's dominant zone 4b supports cauliflower — the key is timing. Cauliflower are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

Does the planting date change across Minnesota?

the far north near International Falls (zone 3a) runs roughly 1-2 weeks behind the state average; the Twin Cities metro and far south (zone 5a) can plant 1-2 weeks earlier.

What else can I plant in Minnesota around the same time?

The same early window suits peas, lettuce, spinach, and onion sets.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.