When to Plant Onion in Hill County, TX
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.
Hill County, Texas is in USDA Zone 8a. The average last spring frost is March 12 and the first fall frost is November 19, giving you a growing season of approximately 252 days.
At an elevation of 2,597 feet, Hill County receives approximately 54.7 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, 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.
Hill County Soil Profile
Soil Type
Clay
Soil pH
7.3-7.7
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.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Onion Planting Timeline — Hill County, TX
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 5 | Feb 5 – Feb 19 |
| Transplant Outdoors | March 12 | Mar 12 – Mar 26 |
| Direct Sow | February 26 | Feb 26 – Mar 19 |
| Fall Sowing | September 10 | Sep 10 – Sep 24 |
| Harvest | June 11 | Jun 11 – Jul 30 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | — |
| June | Harvest |
| July | Harvest |
| August | — |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–120 days
Soil pH
6 – 7
USDA Zone
Zone 8a
Growing Season
252 days
Growing Tips for Hill 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
Level Up Your Garden
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Hill County, TX?
Hill County is in Zone 8a with an average last frost of March 12. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hill County, TX?
Hill County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 12 and first fall frost is November 19.
Plan Your Garden with Confidence
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