When to Plant Onion in Boyd 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.
Boyd County, Kentucky is in USDA Zone 6b. The average last spring frost is April 20 and the first fall frost is October 23, giving you a growing season of approximately 186 days.
At an elevation of 2,124 feet, Boyd County receives approximately 46.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Onion during the growing season.
Boyd County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.5
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 Boyd County
How your county's soil matches Onion's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Onion prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Boyd County is excellent for Onion — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Onion.
Organic Matter
Organic matter is moderate (2.5%). 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
Onion Planting Timeline — Boyd County, KY
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 16 | Mar 16 – Mar 30 |
| Transplant Outdoors | April 20 | Apr 20 – May 4 |
| Direct Sow | April 6 | Apr 6 – Apr 27 |
| Fall Sowing | August 14 | Aug 14 – Aug 28 |
| Harvest | July 20 | Jul 20 – Sep 7 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
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 6b
📆 Growing Season
186 days in Boyd County
Growing Tips for Onion in Boyd County
Direct sow Onion outdoors after April 20 in Boyd 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
Level Up Your Garden
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Boyd County, KY?
Boyd County is in Zone 6b with an average last frost of April 20. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Boyd County, KY?
Boyd County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 20 and first fall frost is October 23.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Boyd County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.