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When to plant Astilbe in Monroe County, MS

Monroe County's 228-day season only supports one Astilbe planting per year. Sow between March 23 and April 6 for the best chance at full maturity before November 6.

When to Plant Astilbe in Monroe County, MS

Monroe County, Mississippi Zone 8a June

Your June gardening checklist

We've pulled the most time-sensitive tasks for Monroe County, Mississippi this June and put them front and centre. Tackle them in order.

Avg. last frost March 23
Avg. first frost November 6
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Bring in the astilbe

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

Coming up in July — start thinking about
  • 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.

Monroe County, Mississippi is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 6, giving you a growing season of approximately 228 days.

At an elevation of 448 feet, Monroe County receives approximately 54.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88°F, providing good warmth for Astilbe during the growing season. Clay soil retains moisture well for Astilbe, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Astilbe root diseases.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Monroe County, MS (Zone 8a) Long season
228 days
Last Spring Frost March 23
228 growing days
First Fall Frost November 6

Monroe County Soil Profile

Soil Type

Clay Loam

Soil pH

5.4-6.7

Drainage

Well Drained

Astilbe Planting Risk Windows

Early Start (70% safe) ✓ Fits season (109 days to spare)
Start indoors: Jan 17 Transplant: Mar 14 🌸 Bloom: May 23 – Jul 11
Recommended (50%) ✓ Fits season (109 days to spare)
Start indoors: Jan 26 Transplant: Mar 23 🌸 Bloom: Jun 1 – Jul 20
Safe Start (90%) ✓ Fits season (108 days to spare)
Start indoors: Feb 16 Transplant: Apr 13 🌸 Bloom: Jun 22 – Aug 10

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 Monroe County

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

Soil pH

Your soil pH (5.4–6.7) overlaps with Astilbe's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Astilbe.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Astilbe.

How to Plant Astilbe

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

Succession Planting Astilbe

3
successive plantings in your 228-day season

Sow every 8 weeks. Last sowing by Jul 29 to harvest before frost.

Astilbe Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 97 gal / 100 sq ft

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 4.4" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 6.5" 6" 0.5" 💧 Light watering
Apr 6.5" 4.7" 1.8" 💧 Light watering
May 6.5" 4.4" 2.1" 💧 Light watering
Jun 6.5" 4.2" 2.3" 💧 Light watering
Jul 6.5" 5.2" 1.3" 💧 Light watering
Aug 6.5" 4.6" 1.9" 💧 Light watering
Sep 6.5" 4.7" 1.8" 💧 Light watering
Oct 6.5" 3.5" 3" 💧 Light watering
Nov 6.5" 3.9" 2.6" 💧 Light watering
Dec 4.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Monroe 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 ~1,360 GDD — county provides 3,648 GDD Excellent fit

Astilbe Planting Timeline — Monroe County, MS

Astilbe Planting Calendar

Activity When Date Range
Start Indoors January 26 Jan 26 – Feb 9
Transplant Outdoors March 23 Mar 23 – Apr 6
Bloom June 1 Jun 1 – Jul 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

228 days in Monroe County

Growing Tips for Astilbe in Monroe County

Direct sow Astilbe outdoors after March 23 in Monroe County when soil has warmed and frost danger has passed.

With Monroe County's clay soil (26% clay), work in 3-4 inches of compost before planting Astilbe. Avoid tilling when soil is wet to prevent compaction.

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 Monroe County, MS?

Monroe County is in Zone 8a with an average last frost of March 23. Plan your Astilbe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, MS?

Monroe County, Mississippi is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 6.

When should I plant Astilbe in Monroe County, MS?

In Monroe County, MS, plant Astilbe after the last frost (around March 23) and before the first frost (around November 6). Best results when soil holds above 50°F.

What growing zone is Monroe County, MS for Astilbe?

Monroe County sits in USDA Zone 8a. Astilbe grows reliably in zones 3a through 8b, so it's a good fit here.

Can Astilbe grow in Monroe County's climate?

Yes — Astilbe grows well in Monroe County's temperate climate. Monroe County averages a 228-day frost-free season, with last frost around March 23 and first frost around November 6.

🌱

Your Monroe County Garden Planner — Free

A 22-page printable planner built for Monroe County (Zone 8a). 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 Monroe County, MS. Local conditions may vary. Last updated: June 2026.

Sources & credits

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