When to plant Ageratum in Dillingham Census Area, AK
Dillingham Census Area sits in cold Zone 4b. Plant Ageratum May 8–May 29 for the single annual harvest; the September 6 first frost closes the window.
When to Plant Ageratum in Dillingham Census Area, AK
What to do in August
Welcome to August in Zone 4b. These are the moves that will have the biggest impact on your growing season.
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.
Dillingham Census Area, Alaska is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is September 6, giving you a growing season of approximately 128 days.
At an elevation of 410 feet, Dillingham Census Area receives approximately 54 inches of rainfall annually with predominantly silt loam soil. Summer highs average 60°F, so choose short-season varieties of Ageratum to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Ageratum root diseases.
Dillingham Census Area Soil Profile
Soil Type
Silt Loam
Soil pH
5-6.2
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 Dillingham Census Area
How your county's soil matches Ageratum's growing requirements.
Soil pH
Your soil pH (5.0–6.2) is more acidic than Ageratum prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Dillingham Census Area is excellent for Ageratum — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Ageratum.
Organic Matter
Organic matter is excellent (6.6%) — Ageratum will thrive.
How to Plant Ageratum
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 | — | 2.6" | 0" | ❄️ Dormant |
| Feb | — | 2.4" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 1.8" | 0" | ❄️ Dormant |
| May | 4.3" | 2.3" | 2" | 💧 Light watering |
| Jun | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Jul | 4.3" | 7.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 9.5" | 0" | ✅ Rainfall sufficient |
| Oct | — | 6.5" | 0" | ❄️ Dormant |
| Nov | — | 4.2" | 0" | ❄️ Dormant |
| Dec | — | 3.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Dillingham Census Area). 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 — Dillingham Census Area, AK
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 13 | Mar 13 – Mar 27 |
| Transplant Outdoors | May 8 | May 8 – May 22 |
| Direct Sow | May 8 | May 8 – May 29 |
| Bloom | July 3 | Jul 3 – Sep 18 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
60–75 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 4b
📆 Growing Season
128 days in Dillingham Census Area
Growing Tips for Ageratum in Dillingham Census Area
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 Dillingham Census Area, AK?
Dillingham Census Area is in Zone 4b with an average last frost of May 1. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dillingham Census Area, AK?
Dillingham Census Area, Alaska is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is September 6.
When should I plant Ageratum in Dillingham Census Area, AK?
In Dillingham Census Area, AK, plant Ageratum after the last frost (around May 1) and before the first frost (around September 6). Best results when soil holds above 50°F.
What growing zone is Dillingham Census Area, AK for Ageratum?
Dillingham Census Area sits in USDA Zone 4b. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.
Can Ageratum grow in Dillingham Census Area's climate?
Yes — Ageratum grows well in Dillingham Census Area's temperate climate. Dillingham Census Area averages a 128-day frost-free season, with last frost around May 1 and first frost around September 6.
Your Dillingham Census Area Garden Planner — Free
A 22-page printable planner built for Dillingham Census Area (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.