When to plant Ageratum in Henderson County, IL
Henderson County's climate puts the Ageratum spring window between April 17 and May 8. time plantings around the expected last-frost window for best survival.
When to Plant Ageratum in Henderson County, IL
Your June gardening checklist
June is a pivotal month for Henderson County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.
-
Get ageratum seeds going inside
These need a head start before your last frost (April 17). Sow into cells now so you're ready to transplant in a few weeks.
-
Harvest ageratum as they ripen
If you can't use it all right away, check the food-preservation section of your planner.
July will be here before you know it — start on
- First harvests: ageratum
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.
Henderson County, Illinois is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.
At an elevation of 1,278 feet, Henderson County receives approximately 41.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Ageratum to ensure they mature before fall.
Henderson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-7.3
Drainage
Well Drained
Ageratum Planting Risk Windows
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 Henderson County
How your county's soil matches Ageratum's growing requirements.
Soil pH
Your soil pH (5.7–7.3) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Henderson County is excellent for Ageratum — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.6%) — Ageratum will thrive.
How to Plant Ageratum
Succession Planting Ageratum
Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.
Ageratum Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| May | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Henderson 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 Planting Timeline — Henderson County, IL
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | April 17 | Apr 17 – May 1 |
| Direct Sow | April 17 | Apr 17 – May 8 |
| Bloom | June 12 | Jun 12 – 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 | Transplant Outdoors Direct Sow |
| 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 6a
📆 Growing Season
183 days in Henderson County
Growing Tips for Ageratum in Henderson County
Direct sow Ageratum outdoors after April 17 in Henderson 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 →
Ageratum in Other Locations
Frequently Asked Questions
When should I plant Ageratum in Henderson County, IL?
Henderson County is in Zone 6a with an average last frost of April 17. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Henderson County, IL?
Henderson County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 17.
When should I plant Ageratum in Henderson County, IL?
In Henderson County, IL, plant Ageratum after the last frost (around April 17) and before the first frost (around October 17). Best results when soil holds above 50°F.
What growing zone is Henderson County, IL for Ageratum?
Henderson County sits in USDA Zone 6a. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.
Can Ageratum grow in Henderson County's climate?
Yes — Ageratum grows well in Henderson County's temperate climate. Henderson County averages a 183-day frost-free season, with last frost around April 17 and first frost around October 17.
Your Henderson County Garden Planner — Free
A 22-page printable planner built for Henderson County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.