When to plant Ageratum in Robertson County, KY
Robertson County's spring Ageratum window runs April 16 through May 7. time plantings around the expected last-frost window for best survival.
When to Plant Ageratum in Robertson 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.
Robertson County, Kentucky is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 26, giving you a growing season of approximately 193 days.
At an elevation of 2,352 feet, Robertson County receives approximately 43 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Ageratum during the growing season.
Robertson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.5
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 | — | 3.9" | 0" | ❄️ Dormant |
| Feb | — | 3.3" | 0" | ❄️ Dormant |
| Mar | — | 4.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| May | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Nov | — | 3.1" | 0" | ❄️ Dormant |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Robertson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Ageratum Planting Timeline — Robertson County, KY
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 26 | Feb 26 – Mar 12 |
| Transplant Outdoors | April 16 | Apr 16 – Apr 30 |
| Direct Sow | April 16 | Apr 16 – May 7 |
| Bloom | June 11 | Jun 11 – Sep 24 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
Moderate — regular watering
📅 Days to Maturity
60–75 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
193 days in Robertson County
Growing Tips for Robertson 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 Robertson County, KY?
Robertson County is in Zone 6b with an average last frost of April 16. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Robertson County, KY?
Robertson County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 26.
When should I plant Ageratum in Robertson County, KY?
In Robertson County, KY, plant Ageratum after the last frost (around April 16) and before the first frost (around October 26). Best results when soil holds above 50°F.
What growing zone is Robertson County, KY for Ageratum?
Robertson 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 Robertson County's climate?
Yes — Ageratum grows well in Robertson County's temperate climate. Robertson County averages a 193-day frost-free season, with last frost around April 16 and first frost around October 26.
Your Robertson County Garden Planner — Free
A 22-page printable planner built for Robertson 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.