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When to Plant Bee Balm in Grand County, CO

Grand County, Colorado Zone 5a May

Your May game plan for Grand County, Colorado

A quick May briefing for Grand County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 28
Avg. first frost September 19
Soil temp (4") 42°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
June prep starts now
  • Transplants going out: bee balm

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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.

Grand County, Colorado is in USDA Zone 5a. The average last spring frost is May 28 and the first fall frost is September 19, giving you a growing season of approximately 114 days.

At an elevation of 5,397 feet, Grand County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Bee Balm to ensure they mature before fall.

Grand County, CO (Zone 5a) Short season
114 days
Last Spring Frost May 28
114 growing days
First Fall Frost September 19
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Grand County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 20 🍅 Harvest: Aug 19 – Nov 4
Recommended (50%) ✗ May not fit
Transplant: Jun 4 🍅 Harvest: Sep 3 – Nov 19
Safe Start (90%) ✗ May not fit
Transplant: Jun 25 🍅 Harvest: Sep 24 – Dec 10

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 Grand County

How your county's soil matches Bee Balm's growing requirements.

Soil pH

Your soil pH (6.7–8.3) is more alkaline than Bee Balm prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Grand County is excellent for Bee Balm — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Bee Balm.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Bee Balm.

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
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 587 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.7" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.3" 2" 💧 Light watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Grand County). Supplement amounts are based on average rainfall — 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" — 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.

Bee Balm needs ~1,208 GDD — county provides 1,311 GDD Good fit

Bee Balm Planting Timeline — Grand County, CO

Bee Balm Planting Calendar

Activity When Date Range
Transplant Outdoors June 4 Jun 4 – Jun 18
Harvest September 3 Sep 3 – Nov 19

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors
July
August
September Harvest
October Harvest
November Harvest
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

114 days in Grand County

Growing Tips for Bee Balm in Grand County

Direct sow Bee Balm outdoors after May 28 in Grand County when soil has warmed and frost danger has passed.

Your 114.0-day growing season in Grand County is tight for Bee Balm (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Grand County receives only 22" of rain annually. Bee Balm needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Grand County, CO?

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

What planting zone is Grand County, CO?

Grand County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 28 and first fall frost is September 19.

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Your Grand County Garden Planner — Free

A 24-page printable planner built for Grand 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.

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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 Grand County, CO. 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.