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When to plant Ageratum in Wayne County, IA

Wayne County sits in USDA Zone 5b. Plant Ageratum between May 3 (after last frost on April 26) and May 24.

When to Plant Ageratum in Wayne County, IA

Wayne County, Iowa Zone 5b July

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Avg. last frost April 26
Avg. first frost October 13
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. It's harvest week for ageratum

    If you can't use it all right away, check the food-preservation section of your planner.

Get ahead of August
  • 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.

Wayne County, Iowa is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 13, giving you a growing season of approximately 170 days.

At an elevation of 901 feet, Wayne County receives approximately 36.3 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
Wayne County, IA (Zone 5b) Moderate season
170 days
Last Spring Frost April 26
170 growing days
First Fall Frost October 13

Wayne County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Start indoors: Feb 26 Transplant: Apr 23 🌸 Bloom: Jun 18 – Sep 17
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Mar 8 Transplant: May 3 🌸 Bloom: Jun 28 – Sep 27
Safe Start (90%) ✓ Fits season (14 days to spare)
Start indoors: Mar 25 Transplant: May 20 🌸 Bloom: Jul 15 – Oct 14

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 Wayne County

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

Soil pH

Your soil pH (5.8–6.9) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Ageratum will thrive.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

3
successive plantings in your 170-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 156 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 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Wayne 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 2,592 GDD Excellent fit

Ageratum Planting Timeline — Wayne County, IA

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors May 3 May 3 – May 17
Direct Sow May 3 May 3 – May 24
Bloom June 28 Jun 28 – Sep 27

· 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
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 5b

📆 Growing Season

170 days in Wayne County

Growing Tips for Ageratum in Wayne County

Direct sow Ageratum outdoors after April 26 in Wayne 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 Wayne County, IA?

Wayne County is in Zone 5b with an average last frost of April 26. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wayne County, IA?

Wayne County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 13.

When should I plant Ageratum in Wayne County, IA?

In Wayne County, IA, plant Ageratum after the last frost (around April 26) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Wayne County, IA for Ageratum?

Wayne 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 Wayne County's climate?

Yes — Ageratum grows well in Wayne County's temperate climate. Wayne County averages a 170-day frost-free season, with last frost around April 26 and first frost around October 13.

🌱

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A 22-page printable planner built for Wayne 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.

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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 Wayne County, IA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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