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When to plant Astilbe in Mathiston, MS

In Mathiston, Astilbe is a single-season spring crop — there's no second fall window. Plant March 23–April 6 for an 100-day harvest, finishing well before the November 7 first frost.

When to Plant Astilbe in Mathiston, MS

Webster County, Mississippi Zone 8a June

Top priorities for Webster County, Mississippi gardeners in June

June is a pivotal month for Webster County, Mississippi gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 23
Avg. first frost November 7
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Collect astilbe at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

July will be here before you know it — start on
  • 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.

Mathiston, Mississippi is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 7, giving you a growing season of approximately 229 days.

At an elevation of 135 feet, Webster County receives approximately 56.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 93°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
Mathiston, MS (Zone 8a) Long season
229 days
Last Spring Frost March 23
229 growing days
First Fall Frost November 7

Mathiston Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Astilbe Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Jan 18 Transplant: Mar 15 🌸 Bloom: May 24 – Jul 12
Recommended (50%) ✓ Fits season (110 days to spare)
Start indoors: Jan 26 Transplant: Mar 23 🌸 Bloom: Jun 1 – Jul 20
Safe Start (90%) ✓ Fits season (109 days to spare)
Start indoors: Feb 15 Transplant: Apr 12 🌸 Bloom: Jun 21 – Aug 9

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 Mathiston

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

Soil pH

Your soil pH (5.6–6.2) is more acidic than Astilbe prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). 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 229-day season

Sow every 8 weeks. Last sowing by Jul 30 to harvest before frost.

Astilbe Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 945 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 5.1" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 6.5" 5.5" 1" 💧 Light watering
Apr 6.5" 3.9" 2.6" 💧 Light watering
May 6.5" 4.1" 2.4" 💧 Light watering
Jun 6.5" 4.9" 1.6" 💧 Light watering
Jul 6.5" 5.4" 1.1" 💧 Light watering
Aug 6.5" 6.2" 0.3" 💧 Light watering
Sep 6.5" 4.6" 1.9" 💧 Light watering
Oct 6.5" 3.9" 2.6" 💧 Light watering
Nov 6.5" 4.6" 1.9" 💧 Light watering
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Webster 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 ~1,679 GDD — county provides 4,522 GDD Excellent fit

Astilbe Planting Timeline — Mathiston, 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 · 1-2 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–8 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8a

📆 Growing Season

229 days in Webster County

Growing Tips for Astilbe in Mathiston

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

With Webster County's clay soil (28% 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 →

When should I plant Astilbe in Mathiston, MS?

In Mathiston, MS, plant Astilbe after the last frost (around March 23) and before the first frost (around November 7). Best results when soil holds above 50°F.

What growing zone is Mathiston, MS for Astilbe?

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

Can Astilbe grow in Mathiston's climate?

Yes — Astilbe grows well in Mathiston's temperate climate. Mathiston averages a 229-day frost-free season, with last frost around March 23 and first frost around November 7.

🌱

Your Webster County Garden Planner — Free

A 22-page printable planner built for Webster 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 Webster County, MS. Local conditions may vary. Last updated: June 2026.