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When to plant Ageratum in Forrest County, MS

Aim to plant Ageratum in Forrest County on or after February 20; the window stays open through March 13. Forrest County's 260-day frost-free season gives you plenty of room for a spring and fall cycle.

When to Plant Ageratum in Forrest County, MS

Forrest County, Mississippi Zone 8b July

July in the garden — Forrest County, Mississippi

We've pulled the most time-sensitive tasks for Forrest County, Mississippi this July and put them front and centre. Tackle them in order.

Avg. last frost March 6
Avg. first frost November 21
Soil temp (4") 90°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Harvest ageratum as they ripen

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

Before August arrives, get these ready
  • 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.

Forrest County, Mississippi is in USDA Zone 8b. The average last spring frost is March 6 and the first fall frost is November 21, giving you a growing season of approximately 260 days.

At an elevation of 125 feet, Forrest County receives approximately 48.9 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, providing good warmth for Ageratum during the growing season. Clay soil retains moisture well for Ageratum, but amend with compost to improve drainage and prevent root rot.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Forrest County, MS (Zone 8b) Long season
260 days
Last Spring Frost March 6
260 growing days
First Fall Frost November 21

Forrest County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (63 days to spare)
Start indoors: Jan 17 Transplant: Feb 14 🌸 Bloom: Apr 11 – Sep 12
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Jan 23 Transplant: Feb 20 🌸 Bloom: Apr 17 – Sep 18
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Feb 12 Transplant: Mar 12 🌸 Bloom: May 7 – Oct 8

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 Forrest County

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

Soil pH

Your soil pH (5.7–6.7) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Ageratum.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

5
successive plantings in your 260-day season

Sow every 6.9 weeks. Last sowing by Sep 07 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 486 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 4.8" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 4.3" 4.5" 0" ✅ Rainfall sufficient
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 4.9" 0" ✅ Rainfall sufficient
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 3.6" 0.7" 💧 Light watering
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Forrest 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 ~1,181 GDD — county provides 4,550 GDD Excellent fit

Ageratum Planting Timeline — Forrest County, MS

Ageratum Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 – Feb 6
Transplant Outdoors February 20 Feb 20 – Mar 6
Direct Sow February 20 Feb 20 – Mar 13
Bloom April 17 Apr 17 – Sep 18

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April Bloom
May Bloom
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 8b

📆 Growing Season

260 days in Forrest County

Growing Tips for Ageratum in Forrest County

Direct sow Ageratum outdoors after March 06 in Forrest County when soil has warmed and frost danger has passed.

With Forrest County's clay soil (27% clay), work in 3-4 inches of compost before planting Ageratum. Avoid tilling when soil is wet to prevent compaction.

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 Forrest County, MS?

Forrest County is in Zone 8b with an average last frost of March 6. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Forrest County, MS?

Forrest County, Mississippi is in USDA Hardiness Zone 8b. The average last spring frost is March 6 and first fall frost is November 21.

When should I plant Ageratum in Forrest County, MS?

In Forrest County, MS, plant Ageratum after the last frost (around March 6) and before the first frost (around November 21). Best results when soil holds above 50°F.

What growing zone is Forrest County, MS for Ageratum?

Forrest County sits in USDA Zone 8b. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Ageratum grow in Forrest County's climate?

Yes — Ageratum grows well in Forrest County's temperate climate. Forrest County averages a 260-day frost-free season, with last frost around March 6 and first frost around November 21.

🌱

Your Forrest County Garden Planner — Free

A 22-page printable planner built for Forrest County (Zone 8b). 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 Forrest County, MS. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.