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When to Plant Onion in Montgomery County, AL

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.

Montgomery County, Alabama is in USDA Zone 8a. The average last spring frost is March 10 and the first fall frost is November 15, giving you a growing season of approximately 250 days.

At an elevation of 468 feet, Montgomery County receives approximately 62 inches of rainfall annually with predominantly clay loam soil. Summer highs average 92ยฐF, 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.

Montgomery County, AL (Zone 8a) Long season
250 days
Last Spring Frost March 10
250 growing days
First Fall Frost November 15

Montgomery County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (110 days to spare)
Start indoors: Jan 29 Transplant: Mar 5 🍅 Harvest: Jun 4 – Jul 23
Recommended (50%) ✓ Fits season (110 days to spare)
Start indoors: Feb 3 Transplant: Mar 10 🍅 Harvest: Jun 9 – Jul 28
Safe Start (90%) ✓ Fits season (105 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: Jun 30 – Aug 18

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 ~1,995 GDD — county provides 4,750 GDD Excellent fit

Onion Planting Timeline โ€” Montgomery County, AL

Onion Planting Calendar

Activity When Date Range
Start Indoors February 3 Feb 3 โ€“ Feb 17
Transplant Outdoors March 10 Mar 10 โ€“ Mar 24
Direct Sow February 24 Feb 24 โ€“ Mar 17
Fall Sowing September 6 Sep 6 โ€“ Sep 20
Harvest June 9 Jun 9 โ€“ Jul 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
April โ€”
May โ€”
June Harvest
July Harvest
August โ€”
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 8a

Growing Season

250 days

Growing Tips for Montgomery 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

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Frequently Asked Questions

When should I plant Onion in Montgomery County, AL?

Montgomery County is in Zone 8a with an average last frost of March 10. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Montgomery County, AL?

Montgomery County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is March 10 and first fall frost is November 15.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Montgomery County gardeners in Zone 8a 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 Montgomery County, AL. Local conditions may vary. Last updated: April 2026.