🧅 When to Plant Green Onion

When should I plant green onion?

Plant green onion outdoors 4 weeks before last frost. For a head start, start seeds indoors 8 weeks before your area's last frost date. Transplants can go out 3 weeks before last frost.

Is green onion frost sensitive?

Green Onion can tolerate light frost, surviving temperatures as low as 35°F. This makes it a great candidate for early spring or fall planting when other crops can't go out yet.

What temperature does green onion need?

Green Onion grows best between 50°F and 80°F. It can survive down to 35°F, but growth slows significantly below 50°F. Warm nights are especially important once fruiting begins.

How long does green onion take to grow?

Green Onion typically takes 60–80 days from transplant (or direct sow) to first harvest.

Should I start green onion seeds indoors?

Yes — start green onion seeds indoors 8 weeks before your area's last expected frost date. This gives seedlings time to develop strong roots before outdoor conditions are ready.

Is it too cold to plant green onion?

It is too cold to plant Green Onion outdoors when nighttime temperatures are falling below 35°F. While Green Onion can tolerate temperatures as low as 35°F, growth will be slow until nights consistently exceed 50°F. Use CanIPlant to check your local 7-day forecast and get a real-time answer for your ZIP code.

Is it too hot to plant green onion?

Green Onion starts to struggle when temperatures climb above 80°F. As a cool-season crop, Green Onion is especially heat-sensitive — high temperatures cause bolting, bitter flavor, or complete crop failure. Avoid planting in the peak of summer and opt for spring or fall instead. CanIPlant checks your local forecast highs to flag this automatically.

Any tips for growing green onion?

Easy and fast. Direct sow in early spring or fall. Harvest young.