When to Plant Spinach in Seminole County, OK
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.
Seminole County, Oklahoma is in USDA Zone 7a. The average last spring frost is March 31 and the first fall frost is November 6, giving you a growing season of approximately 220 days.
At an elevation of 961 feet, Seminole County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Spinach during the growing season.
Seminole County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.5
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 Seminole County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.7–7.5) is within Spinach's preferred range (6.5–7.5).
Soil Texture
The loam soil in Seminole County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Spinach.
How to Plant Spinach
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Spinach
Sow every 4 weeks. Last sowing by Sep 17 to harvest before frost.
For a dedicated fall crop, sow by Aug 28.
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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | 3" | 1.4" | 1.6" | 🚿 Regular watering |
| Apr | 3" | 2.1" | 0.9" | 💧 Light watering |
| May | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 2.4" | 0.6" | 💧 Light watering |
| Aug | 3" | 2.8" | 0.2" | 💧 Light watering |
| Sep | 3" | 1.7" | 1.3" | 💧 Light watering |
| Oct | 3" | 1.3" | 1.7" | 🚿 Regular watering |
| Nov | 3" | 0.8" | 2.2" | 🚿 Regular watering |
| Dec | — | 0.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Seminole 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 — Seminole County, OK
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 24 | Feb 24 – Mar 10 |
| Transplant Outdoors | March 31 | Mar 31 – Apr 14 |
| Direct Sow | March 17 | Mar 17 – Apr 7 |
| Harvest | May 5 | May 5 – Jul 7 |
| Fall Sowing | August 28 | Aug 28 – Sep 11 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · 1-2 times/week
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 7a
📆 Growing Season
220 days in Seminole County
Growing Tips for Spinach in Seminole County
Direct sow Spinach outdoors after March 31 in Seminole County when soil has warmed and frost danger has passed.
Summer highs in Seminole County reach 94°F — grow Spinach as a spring or fall crop. Use shade cloth if planting in summer.
Your generous 220.0-day season in Seminole 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 Seminole 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 Seminole County, OK?
Seminole County is in Zone 7a with an average last frost of March 31. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Seminole County, OK?
Seminole County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is March 31 and first fall frost is November 6.
Plan Your Garden with Confidence
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