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When to Plant Spinach in Sullivan County, TN

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.

Sullivan County, Tennessee is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 19, giving you a growing season of approximately 179 days.

At an elevation of 3,986 feet, Sullivan County receives approximately 46.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Spinach during the growing season.

Sullivan County, TN (Zone 6b) Moderate season
179 days
Last Spring Frost April 23
179 growing days
First Fall Frost October 19

Sullivan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: May 19 – Jul 21
Recommended (50%) ✓ Fits season (81 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: May 28 – Jul 30
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Apr 6 Transplant: May 11 🍅 Harvest: Jun 15 – Aug 17

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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Spinach needs ~616 GDD — county provides 2,595 GDD Excellent fit

Spinach Planting Timeline โ€” Sullivan County, TN

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Direct Sow April 9 Apr 9 โ€“ Apr 30
Fall Sowing August 10 Aug 10 โ€“ Aug 24
Harvest May 28 May 28 โ€“ Jul 30

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors 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 6b

Growing Season

179 days

Growing Tips for Sullivan 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 Sullivan County, TN?

Sullivan County is in Zone 6b with an average last frost of April 23. Plan your Spinach planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sullivan County, TN?

Sullivan County, Tennessee is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sullivan County gardeners in Zone 6b 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 Sullivan County, TN. Local conditions may vary. Last updated: April 2026.