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When to Plant Ageratum in Venango County, PA

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.

Venango County, Pennsylvania is in USDA Zone 6a. The average last spring frost is May 5 and the first fall frost is October 18, giving you a growing season of approximately 166 days.

At an elevation of 1,166 feet, Venango County receives approximately 40.7 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
Venango County, PA (Zone 6a) Moderate season
166 days
Last Spring Frost May 5
166 growing days
First Fall Frost October 18

Venango County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

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 3.3" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 4.2" 0.1" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

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

Ageratum Planting Timeline — Venango County, PA

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

Moderate — regular watering

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

166 days in Venango County

Growing Tips for Venango County

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 Venango County, PA?

Venango 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 Venango County, PA?

Venango County, Pennsylvania is in USDA Hardiness Zone 6a. The average last spring frost is May 5 and first fall frost is October 18.

🌱

Your Venango County Garden Planner — Free

A 22-page printable planner built for Venango 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 Venango County, PA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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