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When to plant Astilbe in Scott County County,

Plant Astilbe in Scott County County during the brief May 2–May 16 window. With 173 frost-free days, fall plantings can't mature before October 15.

When to Plant Astilbe in Scott County, KS

Scott County, Kansas Zone 6a June

What to do in June

Each item below is timed to Scott County, Kansas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 25
Avg. first frost October 15
Soil temp (4") 72°F
Watering High
Pest pressure High
Daylight 14.7 hrs
  1. Time to start astilbe inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

Before July arrives, get these ready
  • First harvests: astilbe

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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.

Scott County, Kansas is in USDA Zone 6a. The average last spring frost is April 25 and the first fall frost is October 15, giving you a growing season of approximately 173 days.

At an elevation of 1,044 feet, Scott County receives approximately 25.4 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Astilbe during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Scott County, KS (Zone 6a) Moderate season
173 days
Last Spring Frost April 25
173 growing days
First Fall Frost October 15
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Scott County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.6

Drainage

Well Drained

Astilbe Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Feb 13 Transplant: Apr 24 🌸 Bloom: Jul 3 – Sep 11
Recommended (50%) ✓ Fits season (26 days to spare)
Start indoors: Feb 21 Transplant: May 2 🌸 Bloom: Jul 11 – Sep 19
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Mar 6 Transplant: May 15 🌸 Bloom: Jul 24 – Oct 2

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 Scott County

How your county's soil matches Astilbe's growing requirements.

Soil pH

Your soil pH (6.4–7.6) is within Astilbe's preferred range (6.0–8.0).

Soil Texture

The loam soil in Scott County is excellent for Astilbe — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Astilbe.

How to Plant Astilbe

1.5"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Astilbe

2
successive plantings in your 173-day season

Sow every 8 weeks. Last sowing by Jul 07 to harvest before frost.

Astilbe Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,632 gal / 100 sq ft
Drought risk

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 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 6.5" 2.6" 3.9" 🚿 Regular watering
May 6.5" 3" 3.5" 🚿 Regular watering
Jun 6.5" 1.6" 4.9" 🚿 Regular watering
Jul 6.5" 2.5" 4" 🚿 Regular watering
Aug 6.5" 2.5" 4" 🚿 Regular watering
Sep 6.5" 2.4" 4.1" 🚿 Regular watering
Oct 6.5" 2" 4.5" 🚿 Regular watering
Nov 1.8" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Scott 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 needs ~1,424 GDD — county provides 2,897 GDD Excellent fit

Astilbe Planting Timeline — Scott County, KS

Astilbe Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors May 2 May 2 – May 16
Bloom July 11 Jul 11 – Sep 19

Plant 1.5" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April
May Transplant Outdoors
June
July Bloom
August Bloom
September Bloom
October
November
December
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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

173 days in Scott County

Growing Tips for Astilbe in Scott County

Direct sow Astilbe outdoors after April 25 in Scott 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 →

Frequently Asked Questions

When should I plant Astilbe in Scott County, KS?

Scott County is in Zone 6a with an average last frost of April 25. Plan your Astilbe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Scott County, KS?

Scott County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 25 and first fall frost is October 15.

When should I plant Astilbe in Scott County County, ?

In Scott County County, , plant Astilbe after the last frost (around April 25) and before the first frost (around October 15). Best results when soil holds above 50°F.

What growing zone is Scott County County, for Astilbe?

Scott County 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 Scott County County's climate?

Yes — Astilbe grows well in Scott County County's temperate climate. Scott County County averages a 173-day frost-free season, with last frost around April 25 and first frost around October 15.

🌱

Your Scott County Garden Planner — Free

A 22-page printable planner built for Scott 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Scott County, KS. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.