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When to Plant Spinach in Miller County, MO

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.

Miller County, Missouri is in USDA Zone 6a. The average last spring frost is April 6 and the first fall frost is October 27, giving you a growing season of approximately 204 days.

At an elevation of 1,086 feet, Miller County receives approximately 30.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Spinach during the growing season.

Miller County, MO (Zone 6a) Long season
204 days
Last Spring Frost April 6
204 growing days
First Fall Frost October 27

Miller County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (105 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: May 5 – Jul 7
Recommended (50%) ✓ Fits season (106 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: May 11 – Jul 13
Safe Start (90%) ✓ Fits season (106 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
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 120 gal / 100 sq ft
Spinach needs ~712 GDD — county provides 3,417 GDD Excellent fit

Spinach Planting Timeline โ€” Miller County, MO

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 โ€“ Mar 16
Transplant Outdoors April 6 Apr 6 โ€“ Apr 20
Direct Sow March 23 Mar 23 โ€“ Apr 13
Fall Sowing August 18 Aug 18 โ€“ Sep 1
Harvest May 11 May 11 โ€“ Jul 13

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 Fall Sowing
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 6a

Growing Season

204 days

Growing Tips for Miller 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 Miller County, MO?

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

What planting zone is Miller County, MO?

Miller County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 6 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

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