When to Plant Onion in Calhoun 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.
Calhoun County, Texas is in USDA Zone 9a. The average last spring frost is February 16 and the first fall frost is December 7, giving you a growing season of approximately 294 days.
At an elevation of 215 feet, Calhoun County receives approximately 59.5 inches of rainfall annually with predominantly loam soil. Summer highs average 99°F, so Onion may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.
Calhoun County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
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
Onion Planting Timeline — Calhoun County, TX
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 19 | Jan 19 – Feb 2 |
| Transplant Outdoors | February 16 | Feb 16 – Mar 2 |
| Direct Sow | January 26 | Jan 26 – Feb 16 |
| Fall Sowing | October 12 | Oct 12 – Oct 26 |
| Harvest | May 18 | May 18 – Jul 6 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| 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 9a
Growing Season
294 days
Growing Tips for Calhoun 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 Calhoun County, TX?
Calhoun County is in Zone 9a with an average last frost of February 16. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Calhoun County, TX?
Calhoun County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 16 and first fall frost is December 7.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Calhoun County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.
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