When to Plant Onion in North Carolina

Growing Onion in North Carolina: Complete Guide

Onion (Allium cepa) is a warm-season crop that needs a head start indoors before North Carolina's last frost. Depending on your zone, North Carolina gardeners start seeds indoors between December 26, 2026 (Zone 9a) and February 18, 2027 (Zone 6b), then move transplants outside once their zone's last frost has passed — the zone table above has your exact dates.

Because North Carolina stretches across 6 USDA hardiness zones (6b, 7a, 7b, 8a, 8b, 9a), 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 100 days to maturity, Onion needs the indoor head start that North Carolina'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. Southeastern summers are hot and humid; mulch heavily to retain moisture and shade roots during peak heat.

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 North Carolina.