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When to Plant Spinach in Washington 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.

Washington County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 25, giving you a growing season of approximately 201 days.

At an elevation of 459 feet, Washington County receives approximately 25 inches of rainfall annually with predominantly loam soil. Summer highs average 92ยฐF, providing good warmth for Spinach during the growing season.

Washington County, OK (Zone 7a) Long season
201 days
Last Spring Frost April 7
201 growing days
First Fall Frost October 25

Washington County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (107 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: May 3 – Jul 5
Recommended (50%) ✓ Fits season (103 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: May 12 – Jul 14
Safe Start (90%) ✓ Fits season (107 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: May 26 – Jul 28

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

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,025 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Spinach needs ~808 GDD — county provides 3,819 GDD Excellent fit

Spinach Planting Timeline โ€” Washington County, OK

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 โ€“ Mar 17
Transplant Outdoors April 7 Apr 7 โ€“ Apr 21
Direct Sow March 24 Mar 24 โ€“ Apr 14
Fall Sowing August 16 Aug 16 โ€“ Aug 30
Harvest May 12 May 12 โ€“ Jul 14

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

35โ€“50 days

Soil pH

6.5 โ€“ 7.5

USDA Zone

Zone 7a

Growing Season

201 days

Growing Tips for Washington County

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.

Companion Planting

Good Companions

Level Up Your Garden

๐ŸŒพ Save Your Own Spinach Seeds
Life Cycle Annual
Pollination Wind Pollinated
How to Collect Let plants bolt. Harvest seed stalks when seeds turn tan.
Storage Store airtight; viable 5 years at 35ยฐF, under 45% humidity.

Wind pollinated โ€” isolate 1/2 mile for purity. Easy to let bolt in heat.

Frequently Asked Questions

When should I plant Spinach in Washington County, OK?

Washington County is in Zone 7a with an average last frost of April 7. Plan your Spinach planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, OK?

Washington County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Washington County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Washington County, OK. Local conditions may vary. Last updated: April 2026.