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When to plant Ageratum in Warren County County,

For Warren County County, gardeners: plant Ageratum April 19 through May 10 once soil reads 50°F.

When to Plant Ageratum in Warren County, IN

Warren County, Indiana Zone 6a June

June in the garden — Warren County, Indiana

Your garden in Warren County, Indiana is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 19
Avg. first frost October 14
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Begin indoor sowing: ageratum

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Bring in the ageratum

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Coming up in July — start thinking about
  • 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.

Warren County, Indiana is in USDA Zone 6a. The average last spring frost is April 19 and the first fall frost is October 14, giving you a growing season of approximately 178 days.

At an elevation of 764 feet, Warren County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Ageratum during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Warren County, IN (Zone 6a) Moderate season
178 days
Last Spring Frost April 19
178 growing days
First Fall Frost October 14
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Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.1

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (24 days to spare)
Start indoors: Feb 24 Transplant: Apr 14 🌸 Bloom: Jun 9 – Sep 15
Recommended (50%) ✓ Fits season (24 days to spare)
Start indoors: Mar 1 Transplant: Apr 19 🌸 Bloom: Jun 14 – Sep 20
Safe Start (90%) ✓ Fits season (23 days to spare)
Start indoors: Mar 17 Transplant: May 5 🌸 Bloom: Jun 30 – Oct 6

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 Warren County

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

Soil pH

Your soil pH (5.9–7.1) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — Ageratum will thrive.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

3
successive plantings in your 178-day season

Sow every 6.9 weeks. Last sowing by Jul 31 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 55 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 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Warren 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 ~979 GDD — county provides 2,581 GDD Excellent fit

Ageratum Planting Timeline — Warren County, IN

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 19 Apr 19 – May 10
Bloom June 14 Jun 14 – Sep 20

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December
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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 6a

📆 Growing Season

178 days in Warren County

Growing Tips for Ageratum in Warren County

Direct sow Ageratum outdoors after April 19 in Warren 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 Warren County, IN?

Warren County is in Zone 6a with an average last frost of April 19. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Warren County, IN?

Warren County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 19 and first fall frost is October 14.

When should I plant Ageratum in Warren County County, ?

In Warren County County, , plant Ageratum after the last frost (around April 19) and before the first frost (around October 14). Best results when soil holds above 50°F.

What growing zone is Warren County County, for Ageratum?

Warren County County sits in USDA Zone 6a. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Ageratum grow in Warren County County's climate?

Yes — Ageratum grows well in Warren County County's temperate climate. Warren County County averages a 178-day frost-free season, with last frost around April 19 and first frost around October 14.

🌱

Your Warren County Garden Planner — Free

A 22-page printable planner built for Warren 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 Warren County, IN. 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.