When to Plant Onion in Fulton County, KY
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.
Fulton County, Kentucky is in USDA Zone 7a. The average last spring frost is March 30 and the first fall frost is October 31, giving you a growing season of approximately 215 days.
At an elevation of 3,261 feet, Fulton County receives approximately 42.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Onion during the growing season.
Fulton County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Plant Planting Risk Windows
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 Fulton County
How your county's soil matches Onion's growing requirements.
Soil pH
Your soil pH (5.7–6.8) overlaps with Onion's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Fulton County is excellent for Onion — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Onion.
How to Plant Onion
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties 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 Planting Timeline — Fulton County, KY
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 23 | Feb 23 – Mar 9 |
| Transplant Outdoors | March 30 | Mar 30 – Apr 13 |
| Direct Sow | March 16 | Mar 16 – Apr 6 |
| Harvest | June 29 | Jun 29 – Aug 17 |
| Fall Sowing | August 22 | Aug 22 – Sep 5 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
215 days in Fulton County
Growing Tips for Onion in Fulton County
Direct sow Onion outdoors after March 30 in Fulton County when soil has warmed and frost danger has passed.
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
Check more plant combinations with our Companion Planting Checker →
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Fulton County, KY?
Fulton County is in Zone 7a with an average last frost of March 30. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fulton County, KY?
Fulton County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is March 30 and first fall frost is October 31.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Fulton County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.
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