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When to plant Spinach in Mahnomen County, MN

For Spinach in Mahnomen County, the safe spring window opens around May 6 and closes around May 27. Last expected frost is May 13, first fall frost September 27, giving a 137-day growing season. A second sowing from July 5 to July 19 extends the harvest into fall.

When to Plant Spinach in Mahnomen County, MN

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.

Mahnomen County, Minnesota is in USDA Zone 4a. The average last spring frost is May 13 and the first fall frost is September 27, giving you a growing season of approximately 137 days.

At an elevation of 1,223 feet, Mahnomen County receives approximately 33.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Spinach to ensure they mature before fall.

Mahnomen County, MN (Zone 4a) Short season
137 days
Last Spring Frost May 13
137 growing days
First Fall Frost September 27

Mahnomen County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7

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 2.2" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 2.4" 0" ❄️ Dormant
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Spinach Planting Timeline — Mahnomen County, MN

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors May 13 May 13 – May 27
Direct Sow May 6 May 6 – May 27
Harvest June 17 Jun 17 – Aug 19
Fall Sowing July 5 Jul 5 – Jul 19

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August 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 4a

📆 Growing Season

137 days in Mahnomen County

Growing Tips for Mahnomen 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 Mahnomen County, MN?

Mahnomen County is in Zone 4a with an average last frost of May 13. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mahnomen County, MN?

Mahnomen County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 13 and first fall frost is September 27.

When should I plant Spinach in Mahnomen County, MN?

In Mahnomen County, MN, plant Spinach after the last frost (around May 13) and before the first frost (around September 27). Best results when soil holds above 50°F.

What growing zone is Mahnomen County, MN for Spinach?

Mahnomen County sits in USDA Zone 4a. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.

Can Spinach grow in Mahnomen County's climate?

Yes — Spinach grows well in Mahnomen County's temperate climate. Mahnomen County averages a 137-day frost-free season, with last frost around May 13 and first frost around September 27.

🌱

Your Mahnomen County Garden Planner — Free

A 22-page printable planner built for Mahnomen County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

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