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When to Plant Lavender in Bay County, MI

Lavender is a fragrant perennial herb with silvery foliage and purple flower spikes. It is prized for its essential oils, culinary uses, and ornamental beauty.

Bay County, Michigan is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.

At an elevation of 835 feet, Bay County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Lavender during the growing season.

Bay County, MI (Zone 5b) Moderate season
150 days
Last Spring Frost May 10
150 growing days
First Fall Frost October 7

Bay County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 8 🍅 Harvest: Aug 7 – Oct 23
Recommended (50%) ✗ May not fit
Transplant: May 17 🍅 Harvest: Aug 16 – Nov 1
Safe Start (90%) ✗ May not fit
Transplant: May 29 🍅 Harvest: Aug 28 – Nov 13

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 Bay County

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

Soil pH

Your soil pH (6.1โ€“6.8) is more acidic than Lavender prefers (6.5โ€“8.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Bay County is excellent for Lavender โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) โ€” Lavender will thrive.

How to Plant Lavender

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

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

Monthly Watering Guide for Lavender

Lavender needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Lavender Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr โ€” 3.1" 0" โ„๏ธ Dormant
May 1.3" 3.8" 0" โœ… Rainfall sufficient
Jun 1.3" 4.5" 0" โœ… Rainfall sufficient
Jul 1.3" 3.5" 0" โœ… Rainfall sufficient
Aug 1.3" 3.7" 0" โœ… Rainfall sufficient
Sep 1.3" 2.9" 0" โœ… Rainfall sufficient
Oct 1.3" 2.3" 0" โœ… Rainfall sufficient
Nov โ€” 2" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

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

Lavender 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.

Lavender needs ~2,211 GDD — county provides 2,287 GDD Good fit

Lavender Planting Timeline โ€” Bay County, MI

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors May 17 May 17 โ€“ May 31
Harvest August 16 Aug 16 โ€“ Nov 1

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 Transplant Outdoors
June โ€”
July โ€”
August Harvest
September Harvest
October Harvest
November Harvest
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“200 days

๐Ÿงช Soil pH

Needs 6.5โ€“8 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

150 days in Bay County

Growing Tips for Lavender in Bay County

Direct sow Lavender outdoors after May 10 in Bay County when soil has warmed and frost danger has passed.

Your 150.0-day growing season in Bay County is tight for Lavender (90.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant in well-drained, sandy soil. Avoid heavy mulching around the crown. Prune after flowering but do not cut into old wood. Lavender resents wet winter conditions.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Bay County, MI?

Bay County is in Zone 5b with an average last frost of May 10. Plan your Lavender planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bay County, MI?

Bay County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bay County gardeners in Zone 5b 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 Bay County, MI. Local conditions may vary. Last updated: April 2026.