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When to Plant Astilbe in Cedar County, NE

Cedar County, Nebraska Zone 5a June

What to do in June

Your Cedar County, Nebraska garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 30
Avg. first frost October 7
Soil temp (4") 65°F
Watering Moderate
Pest pressure High
Daylight 15.1 hrs
To set up a strong July, finish these tasks
  • Starting indoors: astilbe
  • 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.

Cedar County, Nebraska is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.

At an elevation of 899 feet, Cedar County receives approximately 21.1 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Astilbe to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Cedar County, NE (Zone 5a) Moderate season
160 days
Last Spring Frost April 30
160 growing days
First Fall Frost October 7
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Cedar County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.3

Drainage

Well Drained

Astilbe Planting Risk Windows

Early Start (70% safe) ✓ Fits season (9 days to spare)
Start indoors: Feb 19 Transplant: May 7 🌸 Bloom: Jul 23 – Sep 24
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Feb 26 Transplant: May 14 🌸 Bloom: Jul 30 – Oct 1
Safe Start (90%) ✓ Fits season (3 days to spare)
Start indoors: Mar 13 Transplant: May 29 🌸 Bloom: Aug 14 – Oct 16

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 Cedar County

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

Soil pH

Your soil pH (6.5–7.3) is within Astilbe's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Astilbe will thrive.

How to Plant Astilbe

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

Succession Planting Astilbe

2
successive plantings in your 160-day season

Sow every 8 weeks. Last sowing by Jun 29 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 1,617 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 0.5" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 6.5" 2.4" 4.1" 🚿 Regular watering
May 6.5" 2.7" 3.8" 🚿 Regular watering
Jun 6.5" 3.3" 3.2" 💧 Light watering
Jul 6.5" 2.9" 3.6" 🚿 Regular watering
Aug 6.5" 2.4" 4.1" 🚿 Regular watering
Sep 6.5" 1.8" 4.7" 🚿 Regular watering
Oct 6.5" 1.4" 5.1" 🚿 Regular watering
Nov 0.7" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Cedar 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 ~978 GDD — county provides 1,840 GDD Excellent fit

Astilbe Planting Timeline — Cedar County, NE

Astilbe Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors May 14 May 14 – May 28
Bloom July 30 Jul 30 – Oct 1

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 Bloom
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 5a

📆 Growing Season

160 days in Cedar County

Growing Tips for Astilbe in Cedar County

Direct sow Astilbe outdoors after April 30 in Cedar County when soil has warmed and frost danger has passed.

Cedar County receives only 21" 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 →

Frequently Asked Questions

When should I plant Astilbe in Cedar County, NE?

Cedar County is in Zone 5a with an average last frost of April 30. Plan your Astilbe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cedar County, NE?

Cedar County, Nebraska is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 7.

🌱

Your Cedar County Garden Planner — Free

A 22-page printable planner built for Cedar County (Zone 5a). 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 Cedar County, NE. 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.