When to Plant Broccoli in Wisconsin

Growing Broccoli in Wisconsin: Complete Guide

Broccoli (Brassica oleracea var. italica) is a warm-season crop that needs a head start indoors before Wisconsin's last frost. Most Wisconsin gardeners begin seeds indoors around Saturday, March 14, 2026 and move transplants outside around Saturday, April 25, 2026, after the risk of frost has passed.

Because Wisconsin stretches across 6 USDA hardiness zones (3b, 4a, 4b, 5a, 5b, 6a), planting windows can shift by as much as six to eight weeks from one end of the state to the other. Gardeners in the warmer southern zones can start earlier, while those in cooler northern zones should wait until the zone table above shows their last frost has passed.

With 60 days to maturity, Broccoli needs the indoor head start that Wisconsin's growing season requires. Starting indoors ensures you have strong transplants ready the moment outdoor conditions are right.

Broccoli requires full sun (6 hours) and regular (1-1.5 inches/week) moisture. Midwest growing seasons are compressed between late spring frosts and fall cold snaps, so timing transplants precisely pays off.

For the most precise planting dates tailored to your exact location, enter your ZIP code on our planting calendar or use the zone table above to find the schedule for your area of Wisconsin.