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When to Plant Bee Balm in St. Louis County, MN

Bee balm is a native perennial herb with shaggy, scarlet flower heads that attract hummingbirds, bees, and butterflies. Its leaves make an aromatic tea reminiscent of Earl Grey.

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 Bee Balm 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: Jun 4 🍅 Harvest: Sep 3 – Oct 8
Recommended (50%) ✗ May not fit
Transplant: Jun 9 🍅 Harvest: Sep 8 – Oct 13
Safe Start (90%) ✗ May not fit
Transplant: Jun 23 🍅 Harvest: Sep 22 – Oct 27

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 Bee Balm's growing requirements.

Soil pH

Your soil pH (6.0โ€“7.0) is within Bee Balm's preferred range (6.0โ€“7.0).

Soil Texture

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

Drainage

Drainage is adequate for Bee Balm.

Organic Matter

Organic matter is excellent (4.0%) โ€” Bee Balm will thrive.

How to Plant Bee Balm

0.5"
Planting Depth
8"
Between Plants
12"
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 Bee Balm

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

Month Bee Balm 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.

Bee Balm 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.

Bee Balm needs ~892 GDD — county provides 850 GDD Tight fit

Bee Balm Planting Timeline โ€” St. Louis County, MN

Bee Balm Planting Calendar

Activity When Date Range
Transplant Outdoors June 9 Jun 9 โ€“ Jun 23
Harvest September 8 Sep 8 โ€“ Oct 13

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June Transplant Outdoors
July โ€”
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

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 3a

๐Ÿ“† Growing Season

100 days in St. Louis County

Growing Tips for Bee Balm in St. Louis County

Direct sow Bee Balm 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 Bee Balm (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Start from seed, divisions, or transplants. Provide good air circulation to prevent powdery mildew. Deadhead spent flowers for reblooming. Divide clumps every 3 years.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

St. Louis County is in Zone 3a with an average last frost of June 2. Plan your Bee Balm 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.