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When to plant Ageratum in Schoolcraft County, MI

In Schoolcraft County, plant Ageratum in spring between May 21 and June 11, once soil temps hold above 50°F. Schoolcraft County's last frost averages May 14, 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 12.

When to Plant Ageratum in Schoolcraft County, MI

Schoolcraft County, Michigan Zone 5a June

Your June planting checklist for Schoolcraft County, Michigan

A quick June briefing for Schoolcraft County, Michigan gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 14
Avg. first frost October 12
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15.5 hrs
To set up a strong July, finish these tasks
  • Starting indoors: ageratum
  • 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.

Schoolcraft County, Michigan is in USDA Zone 5a. The average last spring frost is May 14 and the first fall frost is October 12, giving you a growing season of approximately 151 days.

At an elevation of 1,121 feet, Schoolcraft County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Ageratum to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Schoolcraft County, MI (Zone 5a) Moderate season
151 days
Last Spring Frost May 14
151 growing days
First Fall Frost October 12

Schoolcraft County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Start indoors: Mar 19 Transplant: May 14 🌸 Bloom: Jul 9 – Oct 1
Recommended (50%) ✓ Fits season (4 days to spare)
Start indoors: Mar 26 Transplant: May 21 🌸 Bloom: Jul 16 – Oct 8
Safe Start (90%) ✓ Fits season (8 days to spare)
Start indoors: Apr 8 Transplant: Jun 3 🌸 Bloom: Jul 29 – 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 Schoolcraft County

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

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Ageratum will thrive.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

2
successive plantings in your 151-day season

Sow every 6.9 weeks. Last sowing by Jul 29 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

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 1.5" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Schoolcraft 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 ~776 GDD — county provides 1,736 GDD Excellent fit

Ageratum Planting Timeline — Schoolcraft County, MI

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors May 21 May 21 – Jun 4
Direct Sow May 21 May 21 – Jun 11
Bloom July 16 Jul 16 – Oct 8

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
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 5a

📆 Growing Season

151 days in Schoolcraft County

Growing Tips for Ageratum in Schoolcraft County

Direct sow Ageratum outdoors after May 14 in Schoolcraft 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 Schoolcraft County, MI?

Schoolcraft County is in Zone 5a with an average last frost of May 14. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Schoolcraft County, MI?

Schoolcraft County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 14 and first fall frost is October 12.

When should I plant Ageratum in Schoolcraft County, MI?

In Schoolcraft County, MI, plant Ageratum after the last frost (around May 14) and before the first frost (around October 12). Best results when soil holds above 50°F.

What growing zone is Schoolcraft County, MI for Ageratum?

Schoolcraft County sits in USDA Zone 5a. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Ageratum grow in Schoolcraft County's climate?

Yes — Ageratum grows well in Schoolcraft County's temperate climate. Schoolcraft County averages a 151-day frost-free season, with last frost around May 14 and first frost around October 12.

🌱

Your Schoolcraft County Garden Planner — Free

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

Sources & credits

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