When to plant Ageratum in Marshall County, KY
Aim to plant Ageratum in Marshall County on or after April 3; the window stays open through April 24. Marshall County's 212-day frost-free season gives you enough for a full main crop and a short fall succession.
When to Plant Ageratum in Marshall County, KY
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.
Marshall County, Kentucky is in USDA Zone 7a. The average last spring frost is April 3 and the first fall frost is November 1, giving you a growing season of approximately 212 days.
At an elevation of 1,550 feet, Marshall County receives approximately 42.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Ageratum during the growing season.
Marshall County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-7.1
Drainage
Well Drained
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 | — | 3.6" | 0" | ❄️ Dormant |
| Feb | — | 4" | 0" | ❄️ Dormant |
| Mar | — | 4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| May | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Jun | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jul | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4" | 0.3" | 💧 Light watering |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | 4.3" | 3" | 1.3" | 💧 Light watering |
| Dec | — | 3.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Marshall County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Ageratum Planting Timeline — Marshall County, KY
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 20 | Feb 20 – Mar 6 |
| Transplant Outdoors | April 3 | Apr 3 – Apr 17 |
| Direct Sow | April 3 | Apr 3 – Apr 24 |
| Bloom | May 29 | May 29 – Sep 18 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
60–75 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 7a
📆 Growing Season
212 days in Marshall County
Growing Tips for Marshall County
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 →
Ageratum in Other Locations
Frequently Asked Questions
When should I plant Ageratum in Marshall County, KY?
Marshall County is in Zone 7a with an average last frost of April 3. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, KY?
Marshall County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 3 and first fall frost is November 1.
When should I plant Ageratum in Marshall County, KY?
In Marshall County, KY, plant Ageratum after the last frost (around April 3) and before the first frost (around November 1). Best results when soil holds above 50°F.
What growing zone is Marshall County, KY for Ageratum?
Marshall County sits in USDA Zone 7a. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.
Can Ageratum grow in Marshall County's climate?
Yes — Ageratum grows well in Marshall County's temperate climate. Marshall County averages a 212-day frost-free season, with last frost around April 3 and first frost around November 1.
Your Marshall County Garden Planner — Free
A 22-page printable planner built for Marshall County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.