When to Plant Onion in Nebraska

Growing Onion in Nebraska: Complete Guide

Onion (Allium cepa) is a warm-season crop that needs a head start indoors before Nebraska's last frost. Most Nebraska gardeners begin seeds indoors around Saturday, February 28, 2026 and move transplants outside around Saturday, May 9, 2026, after the risk of frost has passed.

Because Nebraska stretches across 3 USDA hardiness zones (5a, 5b, 6a), planting windows can shift by as much as two to four 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 100 days to maturity, Onion needs the indoor head start that Nebraska's growing season requires. Starting indoors ensures you have strong transplants ready the moment outdoor conditions are right.

Onion requires full sun (6+ hours) and moderate moisture. Great Plains gardens face strong winds and variable moisture — windbreaks and drip irrigation help significantly.

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 Nebraska.