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When to plant Astilbe in Jackson County County,

In Jackson County County, Astilbe is a single-season spring crop — there's no second fall window. Plant April 21–May 5 for an 100-day harvest, finishing well before the October 22 first frost.

When to Plant Astilbe in Jackson County, KS

Jackson County, Kansas Zone 6a June

June in Jackson County, Kansas — your action list

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Jackson County, Kansas.

Avg. last frost April 14
Avg. first frost October 22
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Time to start astilbe inside

    These need a head start before your last frost (April 14). Sow into cells now so you're ready to transplant in a few weeks.

  2. Harvest astilbe as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

July prep starts now
  • 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.

Jackson County, Kansas is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 22, giving you a growing season of approximately 191 days.

At an elevation of 909 feet, Jackson County receives approximately 25.8 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Astilbe during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Jackson County, KS (Zone 6a) Moderate season
191 days
Last Spring Frost April 14
191 growing days
First Fall Frost October 22

Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Astilbe Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Start indoors: Feb 5 Transplant: Apr 16 🌸 Bloom: Jun 25 – Sep 3
Recommended (50%) ✓ Fits season (44 days to spare)
Start indoors: Feb 10 Transplant: Apr 21 🌸 Bloom: Jun 30 – Sep 8
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Feb 26 Transplant: May 7 🌸 Bloom: Jul 16 – Sep 24

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 Jackson County

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

Soil pH

Your soil pH (6.8–7.8) is within Astilbe's preferred range (6.0–8.0).

Soil Texture

The loam soil in Jackson 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

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

Succession Planting Astilbe

3
successive plantings in your 191-day season

Sow every 8 weeks. Last sowing by Jul 14 to harvest before frost.

Astilbe Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.7″/week
Watering frequency 2-3 times/week
Season total 2,820 gal / 100 sq ft
Drought risk

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 0.7" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 6.5" 2.4" 4.1" 🚿 Regular watering
May 6.5" 3.8" 2.7" 💧 Light watering
Jun 6.5" 4.3" 2.2" 💧 Light watering
Jul 6.5" 3.7" 2.8" 💧 Light watering
Aug 6.5" 3.4" 3.1" 💧 Light watering
Sep 6.5" 2.1" 4.4" 🚿 Regular watering
Oct 6.5" 1.6" 4.9" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jackson 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 ~1,169 GDD — county provides 2,626 GDD Excellent fit

Astilbe Planting Timeline — Jackson County, KS

Astilbe Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors April 21 Apr 21 – May 5
Bloom June 30 Jun 30 – Sep 8

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors
May Transplant Outdoors
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: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

191 days in Jackson County

Growing Tips for Astilbe in Jackson County

Direct sow Astilbe outdoors after April 14 in Jackson 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 Jackson County, KS?

Jackson County is in Zone 6a with an average last frost of April 14. Plan your Astilbe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, KS?

Jackson County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 22.

When should I plant Astilbe in Jackson County County, ?

In Jackson County County, , plant Astilbe after the last frost (around April 14) and before the first frost (around October 22). Best results when soil holds above 50°F.

What growing zone is Jackson County County, for Astilbe?

Jackson 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 Jackson County County's climate?

Yes — Astilbe grows well in Jackson County County's temperate climate. Jackson County County averages a 191-day frost-free season, with last frost around April 14 and first frost around October 22.

🌱

Your Jackson County Garden Planner — Free

A 22-page printable planner built for Jackson 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 Jackson 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.