🧅 Can I Plant Onion in Raleigh, NC?

2026 planting guide for Zone 7b · Last frost ~March 24 · Growing season ~236 days

✅ YES — Good temps, but watch for heat — highs near 90°F

Temperature conditions are suitable for Onion. Highs near 90°F are on the warm side — make sure plants have plenty of water. The season is running warmer than normal, which has opened this window earlier than usual.

Planting window: Jun 27 – Jul 11
Good to go — plant now while conditions are right.
Live result based on current forecast for Raleigh, NC · Updates every 6 hours
USDA Zone
7b
Last Spring Frost
~March 24
First Fall Frost
November 15
Growing Season
~236 days
Ideal Temp for Onion
45–75°F
Frost Risk
✅ Tolerant

Growing Onion in Raleigh

Raleigh's Zone 7b Piedmont location delivers a generous 235 frost-free days. The warm, humid summers are excellent for tomatoes, peppers, and sweet potatoes, while the long fall window supports outstanding cool-season gardens. Many Raleigh gardeners find fall to be their most productive season — planting broccoli, kale, and lettuce in September for harvests through December.

In Raleigh (last frost around March 24), onion can go out around February — approximately 6 weeks before the last expected frost, making it an early-season opportunity. Starting seeds indoors 10 weeks before the last frost date gives you a significant head start.

Onion thrives between 45°F and 75°F. It tolerates temperatures as low as 28°F, making it a candidate for early spring planting before the last frost date. Expect 100–120 days from transplant to first harvest. Long season. Start early indoors or use sets.

Frequently Asked Questions

When can I plant onion in Raleigh, NC?

In Raleigh (last frost around March 24), onion can go out around February — approximately 6 weeks before the last expected frost, making it an early-season opportunity. For best results, start seeds indoors 10 weeks before that — giving you strong transplants ready to go out at the right time.

What is the USDA hardiness zone for Raleigh?

Raleigh, NC is in USDA Plant Hardiness Zone 7b. The last expected spring frost is around March 24, and the first fall frost arrives around November 15. This zone classification helps you understand which perennials survive winter and when annual vegetables can safely go outdoors.

Is it safe to plant onion outside in Raleigh right now?

That depends on the current weather forecast. Onion needs temperatures above 28°F (ideally 45–75°F) to thrive. CanIPlant checks your real 7-day forecast and any active frost alerts to give you a live YES, NO, or WAIT answer — just enter your ZIP code.

Can I grow onion in Raleigh 2026?

Yes — Onion grows well in Raleigh, NC. With a Zone 7b climate and a growing season of ~236 days, Raleigh is well-suited for cool-season crops like onion. As a frost-tolerant crop, onion can even go out a few weeks before the last frost date.

Grow Onion in Other Cities

New York, NYLos Angeles, CAChicago, ILHouston, TXPhoenix, AZPhiladelphia, PASan Antonio, TXSan Diego, CA

Get a live answer for your exact address

Enter your ZIP code — CanIPlant checks your real 7-day forecast, frost alerts, and 30-year climate data to tell you whether to plant onion right now.

Check My ZIP Code →