When to Plant Onion in Hancock County, TN
Your May planting checklist for Hancock County, Tennessee
Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.
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Start onion indoors
You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.
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.
Hancock County, Tennessee is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 22, giving you a growing season of approximately 190 days.
At an elevation of 3,193 feet, Hancock County receives approximately 54.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Onion during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.
Hancock County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.7
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 Hancock County
How your county's soil matches Onion's growing requirements.
Soil pH
Your soil pH (5.4–6.7) overlaps with Onion's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Hancock County is excellent for Onion — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). 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
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 | — | 3.9" | 0" | ❄️ Dormant |
| Mar | — | 4.6" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| May | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 6.2" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Nov | — | 3.8" | 0" | ❄️ Dormant |
| Dec | — | 4.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Hancock 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 Planting Timeline — Hancock County, TN
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 11 | Mar 11 – Mar 25 |
| Transplant Outdoors | April 15 | Apr 15 – Apr 29 |
| Direct Sow | April 1 | Apr 1 – Apr 22 |
| Harvest | July 15 | Jul 15 – Sep 2 |
| Fall Sowing | August 13 | Aug 13 – Aug 27 |
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 | — |
| 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: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
190 days in Hancock County
Growing Tips for Onion in Hancock County
Direct sow Onion outdoors after April 15 in Hancock 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 Hancock County, TN?
Hancock County is in Zone 7a with an average last frost of April 15. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hancock County, TN?
Hancock County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 22.
Your Hancock County Garden Planner — Free
A 24-page printable planner built for Hancock County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.