When to plant Ageratum in Butte County, ID
Plant Ageratum in Butte County, between June 8 and June 29 — the only viable window. Zone 5a's short season (105 frost-free days) rules out a fall crop.
When to Plant Ageratum in Butte County, ID
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.
Butte County, Idaho is in USDA Zone 5a. The average last spring frost is June 1 and the first fall frost is September 14, giving you a growing season of approximately 105 days.
At an elevation of 7,254 feet, Butte County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Ageratum to ensure they mature before fall.
Butte County Soil Profile
Soil Type
Loam
Soil pH
6.8-8.4
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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | — | 2.4" | 0" | ❄️ Dormant |
| May | — | 3" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Jul | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Aug | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Sep | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Oct | — | 2.2" | 0" | ❄️ Dormant |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Butte County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Ageratum Planting Timeline — Butte County, ID
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 13 | Apr 13 – Apr 27 |
| Transplant Outdoors | June 8 | Jun 8 – Jun 22 |
| Direct Sow | June 8 | Jun 8 – Jun 29 |
| Bloom | August 3 | Aug 3 – Oct 26 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | — |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| 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 5a
📆 Growing Season
105 days in Butte County
Growing Tips for Butte 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 Butte County, ID?
Butte County is in Zone 5a with an average last frost of June 1. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Butte County, ID?
Butte County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is June 1 and first fall frost is September 14.
When should I plant Ageratum in Butte County, ID?
In Butte County, ID, plant Ageratum after the last frost (around June 1) and before the first frost (around September 14). Best results when soil holds above 50°F.
What growing zone is Butte County, ID for Ageratum?
Butte County sits in USDA Zone 5a. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.
Can Ageratum grow in Butte County's climate?
Yes — Ageratum grows well in Butte County's temperate climate. Butte County averages a 105-day frost-free season, with last frost around June 1 and first frost around September 14.
Your Butte County Garden Planner — Free
A 22-page printable planner built for Butte County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.