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When to Plant Ageratum in Lake County, OH

Lake County, Ohio Zone 7a June

Top priorities for Lake County, Ohio gardeners in June

We've pulled the most time-sensitive tasks for Lake County, Ohio this June and put them front and centre. Tackle them in order.

Avg. last frost May 5
Avg. first frost October 13
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 15 hrs
  1. Indoor seed-starting week for ageratum

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Basket week: ageratum

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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.

Lake County, Ohio is in USDA Zone 7a. The average last spring frost is May 5 and the first fall frost is October 13, giving you a growing season of approximately 161 days.

At an elevation of 740 feet, Lake County receives approximately 35.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Ageratum during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Lake County, OH (Zone 7a) Moderate season
161 days
Last Spring Frost May 5
161 growing days
First Fall Frost October 13

Lake County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jun 24 – Oct 14
Recommended (50%) ✗ May not fit
Start indoors: Mar 24 Transplant: May 5 🌸 Bloom: Jun 30 – Oct 20
Safe Start (90%) ✗ May not fit
Start indoors: Apr 10 Transplant: May 22 🌸 Bloom: Jul 17 – Nov 6

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 Lake County

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

Soil pH

Your soil pH (6.3–7.2) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Ageratum will thrive.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

3
successive plantings in your 161-day season

Sow every 6.9 weeks. Last sowing by Jul 30 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 95 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 1.7" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 3.9" 0" ❄️ Dormant
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Lake 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 ~1,029 GDD — county provides 2,455 GDD Excellent fit

Ageratum Planting Timeline — Lake County, OH

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors May 5 May 5 – May 19
Direct Sow May 5 May 5 – May 26
Bloom June 30 Jun 30 – Oct 20

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
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 · Only during dry spells

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

161 days in Lake County

Growing Tips for Ageratum in Lake County

Direct sow Ageratum outdoors after May 05 in Lake 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 Lake County, OH?

Lake County is in Zone 7a 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 Lake County, OH?

Lake County, Ohio is in USDA Hardiness Zone 7a. The average last spring frost is May 5 and first fall frost is October 13.

🌱

Your Lake County Garden Planner — Free

A 22-page printable planner built for Lake County (Zone 7a). 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 Lake County, OH. 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.