When to Plant Spinach in Starr County, TX
Spinach is a nutrient-packed cool-season green that grows quickly in spring and fall. It is rich in iron, vitamins, and antioxidants and excellent raw or cooked.
Starr County, Texas is in USDA Zone 9b. The average last spring frost is February 3 and the first fall frost is December 16, giving you a growing season of approximately 316 days.
At an elevation of 2,451 feet, Starr County receives approximately 55.4 inches of rainfall annually with predominantly loam soil. Summer highs average 98°F, so Spinach may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Spinach root diseases.
Starr County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.5
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.
Soil Compatibility in Starr County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.8–7.5) is within Spinach's preferred range (6.5–7.5).
Soil Texture
The loam soil in Starr County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Spinach.
How to Plant Spinach
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Spinach
Sow every 4 weeks. Last sowing by Oct 27 to harvest before frost.
For a dedicated fall crop, sow by Oct 21.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Spinach
Spinach needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Spinach Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 3" | 1.9" | 1.1" | 💧 Light watering |
| Mar | 3" | 3.4" | 0" | ✅ Rainfall sufficient |
| Apr | 3" | 6.6" | 0" | ✅ Rainfall sufficient |
| May | 3" | 8.8" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 7.6" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 7" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 6.4" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 4" | 0" | ✅ Rainfall sufficient |
| Nov | 3" | 1.6" | 1.4" | 💧 Light watering |
| Dec | 3" | 1.6" | 1.4" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Starr County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Spinach Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Spinach Planting Timeline — Starr County, TX
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 6 | Jan 6 – Jan 20 |
| Transplant Outdoors | February 3 | Feb 3 – Feb 17 |
| Direct Sow | January 13 | Jan 13 – Feb 3 |
| Harvest | March 10 | Mar 10 – May 12 |
| Fall Sowing | October 21 | Oct 21 – Nov 4 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | Fall Sowing |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
316 days in Starr County
Growing Tips for Spinach in Starr County
Direct sow Spinach outdoors after February 03 in Starr County when soil has warmed and frost danger has passed.
Summer highs in Starr County reach 98°F — grow Spinach as a spring or fall crop. Use shade cloth if planting in summer.
Your generous 317.0-day season in Starr County allows multiple plantings of Spinach. Sow every 17.0 days for continuous harvest.
General growing tips
Direct sow as soon as soil can be worked in spring. Plant in partial shade for summer crops to delay bolting. Succession plant every 2 weeks for continuous harvest.
Recommended Spinach Varieties for Starr County
Slow-bolting spinach for warm springs — best as fall crop here
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Wind pollinated — isolate 1/2 mile for purity. Easy to let bolt in heat.
Spinach in Other Locations
Frequently Asked Questions
When should I plant Spinach in Starr County, TX?
Starr County is in Zone 9b with an average last frost of February 3. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Starr County, TX?
Starr County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 3 and first fall frost is December 16.
Plan Your Garden with Confidence
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