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When to plant Ageratum in Charlevoix County, MI

In Charlevoix County, plant Ageratum in spring between May 5 and May 26, once soil temps hold above 50°F. Charlevoix County's last frost averages May 5, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 60–75 days before the first frost on October 21.

When to Plant Ageratum in Charlevoix County, MI

Charlevoix County, Michigan Zone 6a June

What to do in June

Your garden in Charlevoix County, Michigan is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 5
Avg. first frost October 21
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 15.4 hrs
  1. Fire up the seed-starting tray: ageratum

    You're about 16 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Pick ageratum

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

Get ahead of July
  • First harvests: ageratum

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Ageratum (Ageratum houstonianum), the floss flower, produces clusters of fluffy, powder-puff blooms in the rare sky-blue and lavender tones difficult to find among warm-season annuals. Compact mounding habit makes it ideal as a front-of-border edging plant. Blooms from early summer through fall with minimal deadheading; heat and humidity tolerant once established.

Charlevoix County, Michigan is in USDA Zone 6a. The average last spring frost is May 5 and the first fall frost is October 21, giving you a growing season of approximately 169 days.

At an elevation of 821 feet, Charlevoix County receives approximately 41.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Ageratum to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Charlevoix County, MI (Zone 6a) Moderate season
169 days
Last Spring Frost May 5
169 growing days
First Fall Frost October 21

Charlevoix County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Start indoors: Mar 9 Transplant: Apr 27 🌸 Bloom: Jun 22 – Sep 28
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Mar 17 Transplant: May 5 🌸 Bloom: Jun 30 – Oct 6
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Apr 1 Transplant: May 20 🌸 Bloom: Jul 15 – Oct 21

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 Charlevoix County

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

Soil pH

Your soil pH (6.0–6.8) is within Ageratum's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Ageratum will thrive.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

3
successive plantings in your 169-day season

Sow every 6.9 weeks. Last sowing by Aug 07 to harvest before frost.

Ageratum Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Ageratum

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

Month Ageratum Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.7" 0" ❄️ Dormant
May 4.3" 5.3" 0" ✅ Rainfall sufficient
Jun 4.3" 5.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

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

Ageratum 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.

Ageratum needs ~878 GDD — county provides 2,197 GDD Excellent fit

Ageratum Planting Timeline — Charlevoix County, MI

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors May 5 May 5 – May 19
Direct Sow May 5 May 5 – May 26
Bloom June 30 Jun 30 – Oct 6

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

169 days in Charlevoix County

Growing Tips for Ageratum in Charlevoix County

Direct sow Ageratum outdoors after May 05 in Charlevoix County when soil has warmed and frost danger has passed.

Common pests for Ageratum in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6–8 weeks before last frost — do not cover seed; it needs light to germinate. Can be direct-sown after last frost once soil warms to 60°F. Transplant or thin to proper spacing after frost danger passes. Deadheading isn't strictly required but tidying spent clusters improves appearance. Provide consistent moisture; drought causes premature setting. Avoid deep shade — blooms best in full sun to light afternoon shade.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Ageratum in Charlevoix County, MI?

Charlevoix County is in Zone 6a with an average last frost of May 5. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Charlevoix County, MI?

Charlevoix County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is May 5 and first fall frost is October 21.

When should I plant Ageratum in Charlevoix County, MI?

In Charlevoix County, MI, plant Ageratum after the last frost (around May 5) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Charlevoix County, MI for Ageratum?

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

Can Ageratum grow in Charlevoix County's climate?

Yes — Ageratum grows well in Charlevoix County's temperate climate. Charlevoix County averages a 169-day frost-free season, with last frost around May 5 and first frost around October 21.

🌱

Your Charlevoix County Garden Planner — Free

A 22-page printable planner built for Charlevoix 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 Charlevoix County, MI. Local conditions may vary. Last updated: June 2026.

Sources & credits

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