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When to Plant Onion in Forsyth County, GA

Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Forsyth County, Georgia is in USDA Zone 7b. The average last spring frost is March 22 and the first fall frost is November 13, giving you a growing season of approximately 236 days.

At an elevation of 59 feet, Forsyth County receives approximately 57.9 inches of rainfall annually with predominantly clay loam soil. Summer highs average 89ยฐF, providing good warmth for Onion during the growing season. Clay soil retains moisture well for Onion, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.

Forsyth County, GA (Zone 7b) Long season
236 days
Last Spring Frost March 22
236 growing days
First Fall Frost November 13

Forsyth County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Start indoors: Feb 5 Transplant: Mar 12 🍅 Harvest: Jun 11 – Jul 30
Recommended (50%) ✓ Fits season (96 days to spare)
Start indoors: Feb 15 Transplant: Mar 22 🍅 Harvest: Jun 21 – Aug 9
Safe Start (90%) ✓ Fits season (96 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jul 8 – Aug 26

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Onion needs ~1,759 GDD — county provides 3,953 GDD Excellent fit

Onion Planting Timeline โ€” Forsyth County, GA

Onion Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 โ€“ Mar 1
Transplant Outdoors March 22 Mar 22 โ€“ Apr 5
Direct Sow March 8 Mar 8 โ€“ Mar 29
Fall Sowing September 4 Sep 4 โ€“ Sep 18
Harvest June 21 Jun 21 โ€“ Aug 9

Plant 1" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors
May โ€”
June Harvest
July Harvest
August Harvest
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7b

Growing Season

236 days

Growing Tips for Forsyth County

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Level Up Your Garden

Frequently Asked Questions

When should I plant Onion in Forsyth County, GA?

Forsyth County is in Zone 7b with an average last frost of March 22. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Forsyth County, GA?

Forsyth County, Georgia is in USDA Hardiness Zone 7b. The average last spring frost is March 22 and first fall frost is November 13.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Forsyth County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Forsyth County, GA. Local conditions may vary. Last updated: April 2026.