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When to Plant Kidney Beans in St. Louis County, MN

Kidney beans are a popular dry bean variety named for their shape, available in red and white types. They are the classic bean for chili and red beans and rice.

St. Louis County, Minnesota is in USDA Zone 3a. 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 78ยฐF, so choose short-season varieties of Kidney Beans to ensure they mature before fall.

St. Louis County, MN (Zone 3a) 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
Transplant: May 28 🍅 Harvest: Aug 27 – Oct 1
Recommended (50%) ✗ May not fit
Transplant: Jun 2 🍅 Harvest: Sep 1 – Oct 6
Safe Start (90%) ✗ May not fit
Transplant: Jun 16 🍅 Harvest: Sep 15 – Oct 20

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 Kidney Beans's growing requirements.

Soil pH

Your soil pH (6.0โ€“7.0) is within Kidney Beans's preferred range (6.0โ€“7.5).

Soil Texture

The silt loam soil in St. Louis County is excellent for Kidney Beans โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Kidney Beans.

Organic Matter

Organic matter is excellent (4.0%) โ€” Kidney Beans will thrive.

How to Plant Kidney Beans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Plant Water Budget

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

Monthly Watering Guide for Kidney Beans

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

Month Kidney Beans Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr โ€” 3.2" 0" โ„๏ธ Dormant
May โ€” 3.9" 0" โ„๏ธ Dormant
Jun 4.3" 5.1" 0" โœ… Rainfall sufficient
Jul 4.3" 4.4" 0" โœ… Rainfall sufficient
Aug 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Sep 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Oct โ€” 2.8" 0" โ„๏ธ Dormant
Nov โ€” 2.3" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in St. Louis County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Kidney Beans 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" โ€” every day above 50ยฐF 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.

Kidney Beans needs ~829 GDD — county provides 850 GDD Good fit

Kidney Beans Planting Timeline โ€” St. Louis County, MN

Kidney Beans Planting Calendar

Activity When Date Range
Direct Sow June 16 Jun 16 โ€“ Jul 7
Harvest September 15 Sep 15 โ€“ Oct 20

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June Direct Sow
July Direct Sow
August โ€”
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

85โ€“110 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 3a

๐Ÿ“† Growing Season

100 days in St. Louis County

Growing Tips for Kidney Beans in St. Louis County

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

Your 100.0-day growing season in St. Louis County is tight for Kidney Beans (85.0-110.0 days to maturity). Start indoors and choose early-maturing varieties.

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

General growing tips

Direct sow after frost. Allow pods to dry completely on the plant. Kidney beans must be thoroughly cooked as raw or undercooked beans contain harmful lectins.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

St. Louis County is in Zone 3a with an average last frost of June 2. Plan your Kidney Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is St. Louis County, MN?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help St. Louis County gardeners in Zone 3a 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 St. Louis County, MN. Local conditions may vary. Last updated: April 2026.