When to Plant Onion in Smith 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.
Smith County, Texas is in USDA Zone 8b. The average last spring frost is March 9 and the first fall frost is November 16, giving you a growing season of approximately 252 days.
At an elevation of 179 feet, Smith County receives approximately 59.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Onion may need afternoon shade and extra watering during peak heat. 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.
Smith County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.6-6.5
Drainage
Well Drained
Monthly Watering Guide for Onion
Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Onion Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Apr | 4.3" | 6.5" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 8.1" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 8.7" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 8.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 6.8" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.2" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Nov | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Smith County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Onion Planting Timeline — Smith County, TX
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 2 | Feb 2 – Feb 16 |
| Transplant Outdoors | March 9 | Mar 9 – Mar 23 |
| Direct Sow | February 23 | Feb 23 – Mar 16 |
| Harvest | June 8 | Jun 8 – Jul 27 |
| Fall Sowing | September 7 | Sep 7 – Sep 21 |
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
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 8b
📆 Growing Season
252 days in Smith County
Growing Tips for Smith 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
Check more plant combinations with our Companion Planting Checker →
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Smith County, TX?
Smith County is in Zone 8b with an average last frost of March 9. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Smith County, TX?
Smith County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 9 and first fall frost is November 16.
Your Smith County Garden Planner — Free
A 22-page printable planner built for Smith County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.