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When to Plant Onion in Bryan County, GA

Bryan County, Georgia Zone 9a May

Top priorities for Bryan County, Georgia gardeners in May

May is a pivotal month for Bryan County, Georgia gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 2
Avg. first frost November 24
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
Looking ahead to June
  • First harvests: onion

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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.

Bryan County, Georgia is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 24, giving you a growing season of approximately 267 days.

At an elevation of 193 feet, Bryan County receives approximately 54 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Onion during the growing season. Sandy soil warms quickly in spring — great for early planting — but Onion will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.

Bryan County, GA (Zone 9a) Long season
267 days
Last Spring Frost March 2
267 growing days
First Fall Frost November 24
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Bryan County Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (136 days to spare)
Start indoors: Jan 17 Transplant: Feb 14 🍅 Harvest: May 16 – Jul 4
Recommended (50%) ✓ Fits season (127 days to spare)
Start indoors: Feb 2 Transplant: Mar 2 🍅 Harvest: Jun 1 – Jul 20
Safe Start (90%) ✓ Fits season (127 days to spare)
Start indoors: Feb 24 Transplant: Mar 24 🍅 Harvest: Jun 23 – Aug 11

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.

Soil Compatibility in Bryan County

How your county's soil matches Onion's growing requirements.

Soil pH

Your soil pH (5.0–6.0) is more acidic than Onion prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Bryan County warms quickly in spring but drains fast. Onion will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Onion.

Organic Matter

Organic matter is low (1.8%). Add 2-3 inches of compost before planting Onion.

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Onion

Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Onion Needs Rainfall You Supplement Action
Jan 4.5" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.3" 5.3" 0" ✅ Rainfall sufficient
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.9" 0" ✅ Rainfall sufficient
Aug 4.3" 5.9" 0" ✅ Rainfall sufficient
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 4.3" 4" 0.3" 💧 Light watering
Dec 4.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Bryan County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Onion Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Onion needs ~1,995 GDD — county provides 5,073 GDD Excellent fit

Onion Planting Timeline — Bryan County, GA

Onion Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors March 2 Mar 2 – Mar 16
Direct Sow February 9 Feb 9 – Mar 2
Harvest June 1 Jun 1 – Jul 20
Fall Sowing September 29 Sep 29 – Oct 13

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

267 days in Bryan County

Growing Tips for Onion in Bryan County

Direct sow Onion outdoors after March 02 in Bryan County when soil has warmed and frost danger has passed.

Sandy soil in Bryan County dries quickly — mulch Onion with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Bryan County, GA?

Bryan County is in Zone 9a with an average last frost of March 2. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bryan County, GA?

Bryan County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 24.

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Your Bryan County Garden Planner — Free

A 24-page printable planner built for Bryan County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Bryan County, GA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.