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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
Season: Apr 10 – Nov 7 (211 days)
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
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 13bFrequently Asked Questions
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.
What is the best month to plant Onion in Zone 7b?
The best time to start Onion in Zone 7b is Jan. Begin seeds indoors around Jan 30, then transplant outdoors after the last frost date of Apr 10.
What companion plants grow well with Onion?
Good companion plants for Onion include Strawberries, Cabbage, Beets, Lettuce, Carrots, Tomatoes. Avoid planting Onion near Beans, Peas.
How long does Onion take to harvest?
Onion takes approximately 110 days from planting to harvest. In Zone 7b, expect your first harvest around Jun 1.
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