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When to Plant Spinach in Door County, WI

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.

Door County, Wisconsin is in USDA Zone 5a. The average last spring frost is May 11 and the first fall frost is October 8, giving you a growing season of approximately 150 days.

At an elevation of 564 feet, Door County receives approximately 41.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Spinach during the growing season.

Door County, WI (Zone 5a) Moderate season
150 days
Last Spring Frost May 11
150 growing days
First Fall Frost October 8

Door County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 9 – Aug 11
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Apr 6 Transplant: May 11 🍅 Harvest: Jun 15 – Aug 17
Safe Start (90%) ✓ Fits season (54 days to spare)
Start indoors: Apr 21 Transplant: May 26 🍅 Harvest: Jun 30 – Sep 1

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
1.2″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 208 gal / 100 sq ft
Drought risk

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

Spinach needs ~648 GDD — county provides 2,287 GDD Excellent fit

Spinach Planting Timeline โ€” Door County, WI

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 โ€“ Apr 20
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow April 27 Apr 27 โ€“ May 18
Fall Sowing July 30 Jul 30 โ€“ Aug 13
Harvest June 15 Jun 15 โ€“ Aug 17

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August Fall Sowing Harvest
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 5a

Growing Season

150 days

Growing Tips for Door 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 Door County, WI?

Door County is in Zone 5a with an average last frost of May 11. Plan your Spinach planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Door County, WI?

Door County, Wisconsin is in USDA Hardiness Zone 5a. The average last spring frost is May 11 and first fall frost is October 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Door County gardeners in Zone 5a 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 Door County, WI. Local conditions may vary. Last updated: April 2026.