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When to plant Spinach in Winnebago County, IA

Plant Spinach in Winnebago County, when soil hits 50°F — usually April 14. Continue planting through May 5 for the spring crop. A second sowing from July 28 to August 11 extends the harvest into fall.

When to Plant Spinach in Winnebago County, IA

Spinach

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.

Winnebago County, Iowa is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 6, giving you a growing season of approximately 161 days.

At an elevation of 520 feet, Winnebago County receives approximately 32.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Spinach to ensure they mature before fall.

Winnebago County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 28
161 growing days
First Fall Frost October 6

Winnebago County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Monthly Watering Guide for Spinach

Spinach needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Spinach Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Winnebago County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Spinach Planting Timeline — Winnebago County, IA

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors April 28 Apr 28 – May 12
Direct Sow April 14 Apr 14 – May 5
Harvest June 2 Jun 2 – Aug 4
Fall Sowing July 28 Jul 28 – Aug 11

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

161 days in Winnebago County

Growing Tips for Winnebago 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

Check more plant combinations with our Companion Planting Checker →

🌾 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 35°F, under 45% humidity.

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

Frequently Asked Questions

When should I plant Spinach in Winnebago County, IA?

Winnebago County is in Zone 5a with an average last frost of April 28. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Winnebago County, IA?

Winnebago County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 6.

When should I plant Spinach in Winnebago County, IA?

In Winnebago County, IA, plant Spinach after the last frost (around April 28) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Winnebago County, IA for Spinach?

Winnebago County sits in USDA Zone 5a. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.

Can Spinach grow in Winnebago County's climate?

Yes — Spinach grows well in Winnebago County's temperate climate. Winnebago County averages a 161-day frost-free season, with last frost around April 28 and first frost around October 6.

🌱

Your Winnebago County Garden Planner — Free

A 22-page printable planner built for Winnebago County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.