When to plant Astilbe in Madison County, AR
Madison County's 206-day season only supports one Astilbe planting per year. Sow between April 13 and April 27 for the best chance at full maturity before October 29.
When to Plant Astilbe in Madison County, AR
Madison County, Arkansas gardeners: here's your June plan
Your garden in Madison County, Arkansas is working on a schedule, even when you're not. Here's where you should be this June.
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Indoor seed-starting week for astilbe
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
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Basket week: astilbe
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Get ahead of July
- 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.
Madison County, Arkansas is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.
At an elevation of 801 feet, Madison County receives approximately 54.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Astilbe during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Astilbe root diseases.
Madison County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.5
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 Madison County
How your county's soil matches Astilbe's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Astilbe prefers (6.0–8.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Madison County is excellent for Astilbe — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.2%). Annual compost additions will help Astilbe.
How to Plant Astilbe
Succession Planting Astilbe
Sow every 8 weeks. Last sowing by Jul 21 to harvest before frost.
Astilbe Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 3.9" | 0" | ❄️ Dormant |
| Feb | — | 4.7" | 0" | ❄️ Dormant |
| Mar | — | 4.4" | 0" | ❄️ Dormant |
| Apr | 6.5" | 4" | 2.5" | 💧 Light watering |
| May | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Jun | 6.5" | 5.1" | 1.4" | 💧 Light watering |
| Jul | 6.5" | 6.3" | 0.2" | 💧 Light watering |
| Aug | 6.5" | 5.7" | 0.8" | 💧 Light watering |
| Sep | 6.5" | 4.4" | 2.1" | 💧 Light watering |
| Oct | 6.5" | 3.1" | 3.4" | 🚿 Regular watering |
| Nov | — | 4.6" | 0" | ❄️ Dormant |
| Dec | — | 3.9" | 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.
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 — Madison County, AR
Astilbe Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 2 | Feb 2 – Feb 16 |
| Transplant Outdoors | April 13 | Apr 13 – Apr 27 |
| Bloom | June 22 | Jun 22 – Aug 17 |
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 | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–8 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7b
📆 Growing Season
206 days in Madison County
Growing Tips for Astilbe in Madison County
Direct sow Astilbe outdoors after April 06 in Madison 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
Frequently Asked Questions
When should I plant Astilbe in Madison County, AR?
Madison County is in Zone 7b with an average last frost of April 6. Plan your Astilbe planting based on this frost date — see the calendar above for exact timing.
What planting zone is Madison County, AR?
Madison County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is October 29.
When should I plant Astilbe in Madison County, AR?
In Madison County, AR, plant Astilbe after the last frost (around April 6) and before the first frost (around October 29). Best results when soil holds above 50°F.
What growing zone is Madison County, AR for Astilbe?
Madison County sits in USDA Zone 7b. Astilbe grows reliably in zones 3a through 8b, so it's a good fit here.
Can Astilbe grow in Madison County's climate?
Yes — Astilbe grows well in Madison County's temperate climate. Madison County averages a 206-day frost-free season, with last frost around April 6 and first frost around October 29.
Your Madison County Garden Planner — Free
A 22-page printable planner built for Madison County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.