When to Plant Onion in Dimmit 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.
Dimmit County, Texas is in USDA Zone 8b. The average last spring frost is February 26 and the first fall frost is December 1, giving you a growing season of approximately 278 days.
At an elevation of 2,638 feet, Dimmit County receives approximately 63.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94°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.
Dimmit County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.3
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
Onion Planting Timeline — Dimmit County, TX
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 22 | Jan 22 – Feb 5 |
| Transplant Outdoors | February 26 | Feb 26 – Mar 12 |
| Direct Sow | February 12 | Feb 12 – Mar 5 |
| Fall Sowing | September 22 | Sep 22 – Oct 6 |
| Harvest | May 28 | May 28 – Jul 16 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| 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 8b
Growing Season
278 days
Growing Tips for Dimmit 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 Dimmit County, TX?
Dimmit County is in Zone 8b with an average last frost of February 26. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dimmit County, TX?
Dimmit County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is February 26 and first fall frost is December 1.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Dimmit County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.
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