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When to plant Ageratum in Rush County, IN

Ageratum planted in Rush County between April 14 and May 5 matures in 60–75 days — well before the October 21 first frost.

When to Plant Ageratum in Rush County, IN

Rush County, Indiana Zone 6a August

Your August gardening checklist

August rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Rush County, Indiana.

Avg. last frost April 14
Avg. first frost October 21
Soil temp (4") 82°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. It's harvest week for ageratum

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

September prep starts now
  • 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.

Rush County, Indiana is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 21, giving you a growing season of approximately 190 days.

At an elevation of 1,033 feet, Rush County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Ageratum during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Rush County, IN (Zone 6a) Moderate season
190 days
Last Spring Frost April 14
190 growing days
First Fall Frost October 21

Rush County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Feb 18 Transplant: Apr 8 🌸 Bloom: Jun 3 – Sep 9
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Feb 24 Transplant: Apr 14 🌸 Bloom: Jun 9 – Sep 15
Safe Start (90%) ✓ Fits season (30 days to spare)
Start indoors: Mar 13 Transplant: May 1 🌸 Bloom: Jun 26 – Oct 2

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 Rush County

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Ageratum.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

3
successive plantings in your 190-day season

Sow every 6.9 weeks. Last sowing by Aug 07 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 177 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 5.1" 0" ✅ Rainfall sufficient
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 3.9" 0.4" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Rush 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 ~1,080 GDD — county provides 3,040 GDD Excellent fit

Ageratum Planting Timeline — Rush County, IN

Ageratum Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors April 14 Apr 14 – Apr 28
Direct Sow April 14 Apr 14 – May 5
Bloom June 9 Jun 9 – Sep 15

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May 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 6a

📆 Growing Season

190 days in Rush County

Growing Tips for Ageratum in Rush County

Direct sow Ageratum outdoors after April 14 in Rush 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 Rush County, IN?

Rush County is in Zone 6a with an average last frost of April 14. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rush County, IN?

Rush County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 21.

When should I plant Ageratum in Rush County, IN?

In Rush County, IN, plant Ageratum after the last frost (around April 14) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Rush County, IN for Ageratum?

Rush 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 Rush County's climate?

Yes — Ageratum grows well in Rush County's temperate climate. Rush County averages a 190-day frost-free season, with last frost around April 14 and first frost around October 21.

🌱

Your Rush County Garden Planner — Free

A 22-page printable planner built for Rush 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 Rush County, IN. Local conditions may vary. Last updated: August 2026.

Sources & credits

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