When to Plant Onion in Somervell 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.
Somervell County, Texas is in USDA Zone 7b. The average last spring frost is March 19 and the first fall frost is November 12, giving you a growing season of approximately 238 days.
At an elevation of 4,773 feet, Somervell County receives approximately 64.7 inches of rainfall annually with predominantly clay soil. Summer highs average 90°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.
Somervell County Soil Profile
Soil Type
Clay
Soil pH
7.2-7.8
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 — Somervell County, TX
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 12 | Feb 12 – Feb 26 |
| Transplant Outdoors | March 19 | Mar 19 – Apr 2 |
| Direct Sow | March 5 | Mar 5 – Mar 26 |
| Fall Sowing | September 3 | Sep 3 – Sep 17 |
| Harvest | June 18 | Jun 18 – Aug 6 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| 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 7b
Growing Season
238 days
Growing Tips for Somervell 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 Somervell County, TX?
Somervell County is in Zone 7b with an average last frost of March 19. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Somervell County, TX?
Somervell County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 19 and first fall frost is November 12.
Plan Your Garden with Confidence
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