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When to Plant Ageratum in Kenora, ON

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.

Kenora, Ontario is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is October 2, giving you a growing season of approximately 140 days.

At an elevation of 1,069 feet, Kenora receives approximately 19.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 73°F, so choose short-season varieties of Ageratum to ensure they mature before fall. Clay soil retains moisture well for Ageratum, but amend with compost to improve drainage and prevent root rot. With low rainfall, drip irrigation is essential for growing Ageratum successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Kenora, ON (Zone 4a) Short season
140 days
Last Spring Frost May 15
140 growing days
First Fall Frost October 2

Kenora Soil Profile

Soil Type

Clay Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Ageratum Planting Timeline — Kenora, ON

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 22 May 22 – Jun 12
Bloom July 17 Jul 17 – Sep 25

· 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
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

140 days in Kenora

Growing Tips for Kenora

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 Kenora, ON?

Kenora is in Zone 4a with an average last frost of May 15. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kenora, ON?

Kenora, Ontario is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is October 2.

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Your Kenora Garden Planner — Free

A 22-page printable planner built for Kenora (Zone 4a). 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 Kenora, ON. Local conditions may vary. Last updated: July 2026.

Sources & credits

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