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When to plant Ageratum in Bethel Census Area, AK

Bethel Census Area sits in cold Zone 4a. Plant Ageratum May 29–June 19 for the single annual harvest; the September 21 first frost closes the window.

When to Plant Ageratum in Bethel Census Area, AK

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.

Bethel Census Area, Alaska is in USDA Zone 4a. The average last spring frost is May 22 and the first fall frost is September 21, giving you a growing season of approximately 122 days.

At an elevation of 1,369 feet, Bethel Census Area receives approximately 50.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 70°F, so choose short-season varieties of Ageratum to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Ageratum root diseases.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Bethel Census Area, AK (Zone 4a) Short season
122 days
Last Spring Frost May 22
122 growing days
First Fall Frost September 21

Bethel Census Area Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Ageratum Planting Timeline — Bethel Census Area, AK

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 29 May 29 – Jun 12
Direct Sow May 29 May 29 – Jun 19
Bloom July 24 Jul 24 – Oct 2

· 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

Moderate — regular watering

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

122 days in Bethel Census Area

Growing Tips for Bethel Census Area

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 Bethel Census Area, AK?

Bethel Census Area is in Zone 4a with an average last frost of May 22. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bethel Census Area, AK?

Bethel Census Area, Alaska is in USDA Hardiness Zone 4a. The average last spring frost is May 22 and first fall frost is September 21.

When should I plant Ageratum in Bethel Census Area, AK?

In Bethel Census Area, AK, plant Ageratum after the last frost (around May 22) and before the first frost (around September 21). Best results when soil holds above 50°F.

What growing zone is Bethel Census Area, AK for Ageratum?

Bethel Census Area sits in USDA Zone 4a. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Ageratum grow in Bethel Census Area's climate?

Yes — Ageratum grows well in Bethel Census Area's temperate climate. Bethel Census Area averages a 122-day frost-free season, with last frost around May 22 and first frost around September 21.

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Your Bethel Census Area Garden Planner — Free

A 22-page printable planner built for Bethel Census Area (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 Bethel Census Area, AK. Local conditions may vary. Last updated: June 2026.

Sources & credits

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