When to plant Astilbe in Sherman County, KS
Sherman County's 162-day season only supports one Astilbe planting per year. Sow between May 9 and May 23 for the best chance at full maturity before October 11.
When to Plant Astilbe in Sherman County, KS
What to do in July
Each item below is timed to Sherman County, Kansas's frost dates and soil temperatures. Skip nothing, stress about nothing.
-
Start astilbe indoors
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
-
Start harvesting astilbe
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Get ahead of August
- 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.
Sherman County, Kansas is in USDA Zone 6a. The average last spring frost is May 2 and the first fall frost is October 11, giving you a growing season of approximately 162 days.
At an elevation of 831 feet, Sherman County receives approximately 24.7 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Astilbe during the growing season.
Sherman County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.3
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 Sherman County
How your county's soil matches Astilbe's growing requirements.
Soil pH
Your soil pH (6.7–7.3) is within Astilbe's preferred range (6.0–8.0).
Soil Texture
The loam soil in Sherman County is excellent for Astilbe — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Astilbe is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.
Organic Matter
Organic matter is excellent (4.1%) — Astilbe will thrive.
How to Plant Astilbe
Succession Planting Astilbe
Sow every 8 weeks. Last sowing by Jul 03 to harvest before frost.
Astilbe Water Budget
Water stress score is 8/10 — 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 | — | 1.9" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 2.3" | 0" | ❄️ Dormant |
| May | 6.5" | 2.7" | 3.8" | 🚿 Regular watering |
| Jun | 6.5" | 1.8" | 4.7" | 🚿 Regular watering |
| Jul | 6.5" | 2.4" | 4.1" | 🚿 Regular watering |
| Aug | 6.5" | 2.8" | 3.7" | 🚿 Regular watering |
| Sep | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Oct | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Nov | — | 1.8" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Sherman 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 — Sherman County, KS
Astilbe Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 28 | Feb 28 – Mar 14 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Bloom | July 18 | Jul 18 – Sep 26 |
Plant 1.5" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| June | — |
| 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: ideal
🗺️ USDA Zone
Zone 6a
📆 Growing Season
162 days in Sherman County
Growing Tips for Astilbe in Sherman County
Direct sow Astilbe outdoors after May 02 in Sherman County when soil has warmed and frost danger has passed.
Sherman County receives only 25" of rain annually. Astilbe needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Sherman County, KS?
Sherman County is in Zone 6a with an average last frost of May 2. Plan your Astilbe planting based on this frost date — see the calendar above for exact timing.
What planting zone is Sherman County, KS?
Sherman County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is May 2 and first fall frost is October 11.
When should I plant Astilbe in Sherman County, KS?
In Sherman County, KS, plant Astilbe after the last frost (around May 2) and before the first frost (around October 11). Best results when soil holds above 50°F.
What growing zone is Sherman County, KS for Astilbe?
Sherman County sits in USDA Zone 6a. Astilbe grows reliably in zones 3a through 8b, so it's a good fit here.
Can Astilbe grow in Sherman County's climate?
Yes — Astilbe grows well in Sherman County's temperate climate. Sherman County averages a 162-day frost-free season, with last frost around May 2 and first frost around October 11.
Your Sherman County Garden Planner — Free
A 22-page printable planner built for Sherman 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.