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When to plant Ageratum in Grant County County,

Grant County County's spring Ageratum window runs April 21 through May 12. time plantings around the expected last-frost window for best survival.

When to Plant Ageratum in Grant County, KS

Grant County, Kansas Zone 6b June

Top priorities for Grant County, Kansas gardeners in June

Each item below is timed to Grant County, Kansas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 21
Avg. first frost October 17
Soil temp (4") 74°F
Watering High
Pest pressure High
Daylight 14.6 hrs
  1. Time to start ageratum inside

    You're about 18 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Basket week: ageratum

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

July will be here before you know it — start on
  • 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.

Grant County, Kansas is in USDA Zone 6b. The average last spring frost is April 21 and the first fall frost is October 17, giving you a growing season of approximately 179 days.

At an elevation of 1,096 feet, Grant County receives approximately 25.2 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Ageratum during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Grant County, KS (Zone 6b) Moderate season
179 days
Last Spring Frost April 21
179 growing days
First Fall Frost October 17

Grant County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Feb 26 Transplant: Apr 16 🌸 Bloom: Jun 11 – Sep 24
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Mar 3 Transplant: Apr 21 🌸 Bloom: Jun 16 – Sep 29
Safe Start (90%) ✓ Fits season (20 days to spare)
Start indoors: Mar 16 Transplant: May 4 🌸 Bloom: Jun 29 – Oct 12

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 Grant County

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

Soil pH

Your soil pH (6.4–7.7) is more alkaline than Ageratum prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Ageratum will thrive.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

3
successive plantings in your 179-day season

Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 781 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.7" 1.6" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Grant 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 ~928 GDD — county provides 2,461 GDD Excellent fit

Ageratum Planting Timeline — Grant County, KS

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 21 Apr 21 – May 12
Bloom June 16 Jun 16 – Sep 29

· 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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

179 days in Grant County

Growing Tips for Ageratum in Grant County

Direct sow Ageratum outdoors after April 21 in Grant 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 Grant County, KS?

Grant County is in Zone 6b with an average last frost of April 21. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, KS?

Grant County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 21 and first fall frost is October 17.

When should I plant Ageratum in Grant County, ?

In Grant County, , plant Ageratum after the last frost (around April 21) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Grant County, for Ageratum?

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

Can Ageratum grow in Grant County's climate?

Yes — Ageratum grows well in Grant County's temperate climate. Grant County averages a 179-day frost-free season, with last frost around April 21 and first frost around October 17.

🌱

Your Grant County Garden Planner — Free

A 22-page printable planner built for Grant County (Zone 6b). 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 Grant County, KS. 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.