When should I plant Onion in Zone 7b?

Start Onion seeds indoors around Jan 30. Transplant outdoors after Mar 13. Expect first harvest around Jun 1.

What is the last frost date for Zone 7b?

The average last spring frost date for Zone 7b is Apr 10. The first fall frost averages Nov 7, giving a 211-day growing season.

Can I grow Onion in Zone 7b?

Yes. Onion needs 110 days to harvest. Zone 7b has a 211-day growing season, which is sufficient.

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🧅 Growing Onion in Zone 7b

Zone 7b has mild winters and a long growing season — good conditions for Onion. Last frost: Apr 10. First frost: Nov 7.

Planting Calendar

Indoor

Outdoor

Harvest

Jan 30Nov 7

Season: Apr 10 – Nov 7 (211 days)

Zone7b

Last FrostApr 10

First FrostNov 7

Season Length211 days

Days to Harvest110

SunFull Sun

Frost ToleranceModerate

Spacing9/sqft (4" apart)

When to Plant Onion in Zone 7b

Start Seeds Indoors: Jan 30

Start Onion seeds indoors around Jan 30 (10 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 7–14 days.

Transplant Outdoors: Mar 13

Transplant Onion seedlings outdoors after Mar 13. Wait until soil temperature reaches 45°F. Space plants at 9/sqft (4" apart). Harden off plants for a week before moving outside.

Harvest: Jun 1

First harvest approximately Jun 1 (~80 days from transplant). Continue harvesting until first frost (Nov 7).

Companion Planting

✅ Strawberries✅ Cabbage✅ Beets✅ Lettuce✅ Carrots✅ Tomatoes

❌ Beans❌ Peas

Onion in Other Zones

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Plan Your Onion Garden

Track Onion from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Onion Growing Guide