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When to plant Sweet Alyssum in Bay County County,

In Bay County County, plant Sweet Alyssum in spring between April 19 and May 10, once soil temps hold above 50°F. Bay County County's last frost averages May 10, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 60 days before the first frost on October 7.

When to Plant Sweet Alyssum in Bay County, MI

Bay County, Michigan Zone 6a June

Bay County, Michigan gardeners: here's your June plan

Here's what deserves your attention in Bay County, Michigan this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost May 10
Avg. first frost October 7
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
  1. Begin indoor sowing: sweet alyssum

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Pick sweet alyssum

    If you can't use it all right away, check the food-preservation section of your planner.

A few tasks this June that'll pay off in July
  • First harvests: sweet alyssum

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Sweet Alyssum (Lobularia maritima) is a low-growing cool-season annual prized for its honey-scented clusters of tiny white, pink, or purple flowers. A workhorse border plant, it tolerates light frost, self-seeds readily, and attracts beneficial insects throughout its bloom season. In warm climates it often re-blooms in fall after summer heat fades.

Bay County, Michigan is in USDA Zone 6a. 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 87°F, providing good warmth for Sweet Alyssum during the growing season.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Fragrant
Bay County, MI (Zone 6a) 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

Sweet Alyssum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Start indoors: Mar 13 Transplant: May 1 🌸 Bloom: Jun 12 – Aug 21
Recommended (50%) ✓ Fits season (38 days to spare)
Start indoors: Mar 22 Transplant: May 10 🌸 Bloom: Jun 21 – Aug 30
Safe Start (90%) ✓ Fits season (40 days to spare)
Start indoors: Apr 3 Transplant: May 22 🌸 Bloom: Jul 3 – Sep 11

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 Sweet Alyssum's growing requirements.

Soil pH

Your soil pH (6.1–6.8) is within Sweet Alyssum's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Bay County is excellent for Sweet Alyssum — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) — Sweet Alyssum will thrive.

How to Plant Sweet Alyssum

6"
Between Plants
8"
Between Rows

Succession Planting Sweet Alyssum

3
successive plantings in your 150-day season

Sow every 5.1 weeks. Last sowing by Aug 08 to harvest before frost.

Sweet Alyssum Water Budget

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

Monthly Watering Guide for Sweet Alyssum

Sweet Alyssum needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Sweet Alyssum Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 2.2" 3.8" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 3.5" 0" ✅ Rainfall sufficient
Aug 2.2" 3.7" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.3" 0" ✅ Rainfall sufficient
Nov 2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

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

Sweet Alyssum 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.

Sweet Alyssum needs ~801 GDD — county provides 2,287 GDD Excellent fit

Sweet Alyssum Planting Timeline — Bay County, MI

Sweet Alyssum Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 19 Apr 19 – May 10
Bloom June 21 Jun 21 – Aug 30

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

150 days in Bay County

Growing Tips for Sweet Alyssum in Bay County

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

Common pests for Sweet Alyssum in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Surface-sow seeds — they need light to germinate. Direct-sow as soon as soil can be worked in spring; in zones 7+ also sow in fall. Thin to 6 inches apart. Shear back hard in midsummer when heat causes dormancy — plants recover and re-bloom when cool weather returns. Self-seeds prolifically; allow a few plants to set seed for a perpetual colony.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Alyssum in Bay County, MI?

Bay County is in Zone 6a with an average last frost of May 10. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bay County, MI?

Bay County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 7.

When should I plant Sweet Alyssum in Bay County County, ?

In Bay County County, , plant Sweet Alyssum after the last frost (around May 10) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Bay County County, for Sweet Alyssum?

Bay County County sits in USDA Zone 6a. Sweet Alyssum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Sweet Alyssum grow in Bay County County's climate?

Yes — Sweet Alyssum grows well in Bay County County's temperate climate. Bay County County averages a 150-day frost-free season, with last frost around May 10 and first frost around October 7.

🌱

Your Bay County Garden Planner — Free

A 22-page printable planner built for Bay County (Zone 6a). 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 Bay County, MI. Local conditions may vary. Last updated: June 2026.

Sources & credits

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