When to Plant Onion in Cass 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.
Cass County, Texas is in USDA Zone 8a. The average last spring frost is March 14 and the first fall frost is November 16, giving you a growing season of approximately 247 days.
At an elevation of 392 feet, Cass County receives approximately 71.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Onion during the growing season. Sandy soil warms quickly in spring — great for early planting — but Onion will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.
Cass County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.6-6.7
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.
Plant Water Budget
Onion Planting Timeline — Cass County, TX
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 7 | Feb 7 – Feb 21 |
| Transplant Outdoors | March 14 | Mar 14 – Mar 28 |
| Direct Sow | February 28 | Feb 28 – Mar 21 |
| Fall Sowing | September 7 | Sep 7 – Sep 21 |
| Harvest | June 13 | Jun 13 – Aug 1 |
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 | 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 8a
Growing Season
247 days
Growing Tips for Cass 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 Cass County, TX?
Cass County is in Zone 8a with an average last frost of March 14. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Cass County, TX?
Cass County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 14 and first fall frost is November 16.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Cass County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.
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