When to plant Ageratum in Madison County County,
For Madison County County, gardeners: plant Ageratum April 11 through May 2 once soil reads 50°F.
When to Plant Ageratum in Madison County, IL
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.
Madison County, Illinois is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 22, giving you a growing season of approximately 194 days.
At an elevation of 963 feet, Madison County receives approximately 36.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Ageratum during the growing season.
Madison County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.9
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4" | 0.3" | 💧 Light watering |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Aug | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Sep | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Madison County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Ageratum Planting Timeline — Madison County, IL
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 28 | Feb 28 – Mar 14 |
| Transplant Outdoors | April 11 | Apr 11 – Apr 25 |
| Direct Sow | April 11 | Apr 11 – May 2 |
| Bloom | June 6 | Jun 6 – Sep 26 |
· 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 7a
📆 Growing Season
194 days in Madison County
Growing Tips for Madison 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 Madison County, IL?
Madison County is in Zone 7a with an average last frost of April 11. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Madison County, IL?
Madison County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 22.
When should I plant Ageratum in Madison County County, ?
In Madison County County, , plant Ageratum after the last frost (around April 11) and before the first frost (around October 22). Best results when soil holds above 50°F.
What growing zone is Madison County County, for Ageratum?
Madison County 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 Madison County County's climate?
Yes — Ageratum grows well in Madison County County's temperate climate. Madison County County averages a 194-day frost-free season, with last frost around April 11 and first frost around October 22.
Your Madison County Garden Planner — Free
A 22-page printable planner built for Madison 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.