Blog

When to plant Ageratum in York County, ME

Spring Ageratum in York County goes in May 14–June 4, once nighttime temps stop dipping near freezing.

When to Plant Ageratum in York County, ME

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.

York County, Maine is in USDA Zone 5b. The average last spring frost is May 7 and the first fall frost is October 8, giving you a growing season of approximately 154 days.

At an elevation of 794 feet, York County receives approximately 47.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Ageratum to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
York County, ME (Zone 5b) Moderate season
154 days
Last Spring Frost May 7
154 growing days
First Fall Frost October 8

York County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Ageratum Planting Timeline — York County, ME

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors May 14 May 14 – May 28
Direct Sow May 14 May 14 – Jun 4
Bloom July 9 Jul 9 – 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 Direct Sow
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 5b

📆 Growing Season

154 days in York County

Growing Tips for York 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 York County, ME?

York County is in Zone 5b with an average last frost of May 7. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is York County, ME?

York County, Maine is in USDA Hardiness Zone 5b. The average last spring frost is May 7 and first fall frost is October 8.

When should I plant Ageratum in York County, ME?

In York County, ME, plant Ageratum after the last frost (around May 7) and before the first frost (around October 8). Best results when soil holds above 50°F.

What growing zone is York County, ME for Ageratum?

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

Can Ageratum grow in York County's climate?

Yes — Ageratum grows well in York County's temperate climate. York County averages a 154-day frost-free season, with last frost around May 7 and first frost around October 8.

🌱

Your York County Garden Planner — Free

A 22-page printable planner built for York County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for York County, ME. 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.