When to plant Astilbe in Devils Elbow, MO
In Devils Elbow, Astilbe is a single-season spring crop — there's no second fall window. Plant April 16–April 30 for an 70–100-day harvest, finishing well before the October 25 first frost.
When to Plant Astilbe in Devils Elbow, MO
Your July gardening checklist
If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.
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Start harvesting astilbe
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
August prep starts now
- First harvests: astilbe
Astilbe (Astilbe x arendsii) is a premier perennial for shaded, moist gardens, producing feathery plume-like flower spikes in shades of pink, red, white, and lavender above deeply cut, ferny foliage. Originating in Asia and naturalized in shade gardens worldwide, astilbe thrives where many sun-lovers fail: under trees, beside water features, or in persistently moist woodland borders. The dried flower plumes remain attractive through fall and winter. Different cultivars extend the bloom season from early summer through early fall when several varieties are combined.
Devils Elbow, Missouri is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.
At an elevation of 877 feet, Pulaski County receives approximately 35.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Astilbe during the growing season.
Devils Elbow Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.6
Drainage
Well Drained
Astilbe 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 Devils Elbow
How your county's soil matches Astilbe's growing requirements.
Soil pH
Your soil pH (5.4–6.6) overlaps with Astilbe's range (6.0–8.0), though not a perfect match.
Soil Texture
The silt loam soil in Pulaski County is excellent for Astilbe — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Astilbe.
How to Plant Astilbe
Succession Planting Astilbe
Sow every 8 weeks. Last sowing by Jul 17 to harvest before frost.
Astilbe Water Budget
Monthly Watering Guide for Astilbe
Astilbe needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Astilbe Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| May | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| Jun | 6.5" | 4.6" | 1.9" | 💧 Light watering |
| Jul | 6.5" | 4.4" | 2.1" | 💧 Light watering |
| Aug | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| Sep | 6.5" | 2.9" | 3.6" | 🚿 Regular watering |
| Oct | 6.5" | 2.9" | 3.6" | 🚿 Regular watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Pulaski County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Astilbe 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.
Astilbe Planting Timeline — Devils Elbow, MO
Astilbe Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 5 | Feb 5 – Feb 19 |
| Transplant Outdoors | April 16 | Apr 16 – Apr 30 |
| Bloom | June 25 | Jun 25 – Sep 3 |
Plant 1.5" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–8 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
199 days in Pulaski County
Growing Tips for Astilbe in Devils Elbow
Direct sow Astilbe outdoors after April 09 in Pulaski County when soil has warmed and frost danger has passed.
General growing tips
Plant bare-root crowns in spring as soon as the ground is workable, setting eyes 1–2 inches below soil level. Fall planting (Zones 4+) is equally effective. Consistent moisture is non-negotiable — astilbe will wilt and scorch in drought. Amend with generous compost to improve moisture retention. Partial shade (morning sun, afternoon shade) is ideal; deep shade reduces bloom but foliage remains. Fertilize lightly in spring with a balanced slow-release granular. Divide every 3–5 years in early spring as clumps become congested. Leave plumes standing through winter for ornamental interest and wildlife value. Year 2+ plants produce the fullest bloom spikes; first-year crowns may flower lightly or not at all.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Astilbe in Other Locations
When should I plant Astilbe in Devils Elbow, MO?
In Devils Elbow, MO, plant Astilbe after the last frost (around April 9) and before the first frost (around October 25). Best results when soil holds above 50°F.
What growing zone is Devils Elbow, MO for Astilbe?
Devils Elbow sits in USDA Zone 6b. Astilbe grows reliably in zones 3a through 8b, so it's a good fit here.
Can Astilbe grow in Devils Elbow's climate?
Yes — Astilbe grows well in Devils Elbow's temperate climate. Devils Elbow averages a 199-day frost-free season, with last frost around April 9 and first frost around October 25.
Your Pulaski County Garden Planner — Free
A 22-page printable planner built for Pulaski 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.