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When to Plant Ageratum in Dickson County, TN

Dickson County, Tennessee Zone 7b June

June to-do list for Dickson County, Tennessee

June is a pivotal month for Dickson County, Tennessee gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 4
Avg. first frost October 29
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.4 hrs
  1. Collect ageratum at their peak

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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.

Dickson County, Tennessee is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is October 29, giving you a growing season of approximately 208 days.

At an elevation of 2,147 feet, Dickson County receives approximately 54 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Ageratum during the growing season. 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
Dickson County, TN (Zone 7b) Long season
208 days
Last Spring Frost April 4
208 growing days
First Fall Frost October 29

Dickson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Start indoors: Feb 14 Transplant: Mar 28 🌸 Bloom: May 23 – Sep 26
Recommended (50%) ✓ Fits season (26 days to spare)
Start indoors: Feb 21 Transplant: Apr 4 🌸 Bloom: May 30 – Oct 3
Safe Start (90%) ✓ Fits season (28 days to spare)
Start indoors: Mar 7 Transplant: Apr 18 🌸 Bloom: Jun 13 – Oct 17

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 Dickson County

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

Soil pH

Your soil pH (5.6–6.7) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Ageratum.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

4
successive plantings in your 208-day season

Sow every 6.9 weeks. Last sowing by Aug 15 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 4.7" 0" ❄️ Dormant
Feb 4.4" 0" ❄️ Dormant
Mar 5.3" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 5.5" 0" ✅ Rainfall sufficient
Jul 4.3" 5.1" 0" ✅ Rainfall sufficient
Aug 4.3" 5.4" 0" ✅ Rainfall sufficient
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 4" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Dickson 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 ~1,282 GDD — county provides 3,952 GDD Excellent fit

Ageratum Planting Timeline — Dickson County, TN

Ageratum Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow April 4 Apr 4 – Apr 25
Bloom May 30 May 30 – Oct 3

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

208 days in Dickson County

Growing Tips for Ageratum in Dickson County

Direct sow Ageratum outdoors after April 04 in Dickson 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 Dickson County, TN?

Dickson County is in Zone 7b with an average last frost of April 4. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dickson County, TN?

Dickson County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is October 29.

🌱

Your Dickson County Garden Planner — Free

A 22-page printable planner built for Dickson County (Zone 7b). 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 Dickson County, TN. 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.