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When to Plant Peas in St. Louis County, MN

St. Louis County, Minnesota Zone 3b May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in St. Louis County, Minnesota.

Avg. last frost June 2
Avg. first frost September 10
Soil temp (4") 49°F
Watering Low
Pest pressure Low
Daylight 14.9 hrs
  1. Outdoor sowing time: peas

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

Coming up in June — start thinking about
  • Transplants going out: peas
  • Fall sowing: peas

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Peas are a cool-season legume that fixes nitrogen in the soil. Garden peas are shelled, while snap and snow peas are eaten pod and all.

St. Louis County, Minnesota is in USDA Zone 3b. The average last spring frost is June 2 and the first fall frost is September 10, giving you a growing season of approximately 100 days.

At an elevation of 531 feet, St. Louis County receives approximately 36.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 78°F, so choose short-season varieties of Peas to ensure they mature before fall.

St. Louis County, MN (Zone 3b) Short season
100 days
Last Spring Frost June 2
100 growing days
First Fall Frost September 10

St. Louis County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 16 Transplant: May 28 🍅 Harvest: Jul 23 – Sep 17
Recommended (50%) ✗ May not fit
Start indoors: Apr 21 Transplant: Jun 2 🍅 Harvest: Jul 28 – Sep 22
Safe Start (90%) ✗ May not fit
Start indoors: May 5 Transplant: Jun 16 🍅 Harvest: Aug 11 – Oct 6

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.

Soil Compatibility in St. Louis County

How your county's soil matches Peas's growing requirements.

Soil pH

Your soil pH (6.0–7.0) is within Peas's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in St. Louis County is excellent for Peas — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Peas.

Organic Matter

Organic matter is excellent (4.0%) — Peas will thrive.

How to Plant Peas

1"
Planting Depth
4"
Between Plants
18"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Peas

2
successive plantings in your 100-day season

Sow every 6.3 weeks. Last sowing by Jul 02 to harvest before frost.

For a dedicated fall crop, sow by Jun 18.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
1.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Peas

Peas needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Peas Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 3.9" 0" ❄️ Dormant
Jun 3" 5.1" 0" ✅ Rainfall sufficient
Jul 3" 4.4" 0" ✅ Rainfall sufficient
Aug 3" 3.7" 0" ✅ Rainfall sufficient
Sep 3" 3.1" 0" ✅ Rainfall sufficient
Oct 2.8" 0" ❄️ Dormant
Nov 2.3" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

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

Peas Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Peas needs ~531 GDD — county provides 850 GDD Excellent fit

Peas Planting Timeline — St. Louis County, MN

Peas Planting Calendar

Activity When Date Range
Start Indoors April 21 Apr 21 – May 5
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest July 28 Jul 28 – Sep 22
Fall Sowing June 18 Jun 18 – Jul 2

Plant 1" deep · 4" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 3b

📆 Growing Season

100 days in St. Louis County

Growing Tips for Peas in St. Louis County

Direct sow Peas outdoors after June 02 in St. Louis County when soil has warmed and frost danger has passed.

Common pests for Peas in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow as early as soil can be worked in spring. Inoculate seeds with rhizobium for best nitrogen fixation. Provide trellising for climbing varieties.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Peas Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let pods dry brown and papery on the vine.
Storage Store airtight; viable 3 years at 35°F, under 45% humidity.

Very easy to save. Self-pollinating means varieties stay true.

Frequently Asked Questions

When should I plant Peas in St. Louis County, MN?

St. Louis County is in Zone 3b with an average last frost of June 2. Plan your Peas planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Louis County, MN?

St. Louis County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is June 2 and first fall frost is September 10.

🌱

Your St. Louis County Garden Planner — Free

A 24-page printable planner built for St. Louis County (Zone 3b). 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 St. Louis County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

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