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When to plant Sedum (Stonecrop) in Castleton, IL

In Castleton, Sedum (Stonecrop) is a spring-only crop. Plant May 5–May 19 once soil hits 50°F.

When to Plant Sedum (Stonecrop) in Castleton, IL

Stark County, Illinois Zone 5b July

Stark County, Illinois gardeners: here's your July plan

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

Avg. last frost April 21
Avg. first frost October 12
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 14.7 hrs

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Sedum (Hylotelephium spectabile, formerly Sedum spectabile) is a supremely tough, drought-tolerant perennial prized for its late-season interest. The flat-topped clusters of starry flowers open pink in late summer and deepen to copper-red as temperatures cool, remaining attractive well into fall and providing seed heads that feed birds through winter. Succulent foliage emerges blue-green in spring, is handsome all season, and turns bronzy after frost. Remarkably adaptable — thrives in poor, gravelly, or sandy soils where other perennials struggle — and virtually maintenance-free once established.

Castleton, Illinois is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 12, giving you a growing season of approximately 174 days.

At an elevation of 1,071 feet, Stark County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Sedum (Stonecrop) to ensure they mature before fall.

Perennial Blooms in Fall Pollinator-friendly Deer-resistant Good for cutting
Castleton, IL (Zone 5b) Moderate season
174 days
Last Spring Frost April 21
174 growing days
First Fall Frost October 12

Castleton Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Sedum (Stonecrop) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 12 Transplant: Apr 30 🌸 Bloom: Aug 27 – Nov 5
Recommended (50%) ✗ May not fit
Start indoors: Feb 17 Transplant: May 5 🌸 Bloom: Sep 1 – Nov 10
Safe Start (90%) ✗ May not fit
Start indoors: Mar 6 Transplant: May 22 🌸 Bloom: Sep 18 – Nov 27

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 Castleton

How your county's soil matches Sedum (Stonecrop)'s growing requirements.

Soil pH

Your soil pH (6.0–6.9) is within Sedum (Stonecrop)'s preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Stark County is excellent for Sedum (Stonecrop) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.8%) — Sedum (Stonecrop) will thrive.

How to Plant Sedum (Stonecrop)

1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Sedum (Stonecrop)

3
successive plantings in your 174-day season

Sow every 6.9 weeks. Last sowing by Jul 14 to harvest before frost.

Sedum (Stonecrop) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sedum (Stonecrop)

Sedum (Stonecrop) needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Sedum (Stonecrop) Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.5" 0" ✅ Rainfall sufficient
Aug 2.2" 3.3" 0" ✅ Rainfall sufficient
Sep 2.2" 2.8" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.3" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Stark County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sedum (Stonecrop) 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.

Sedum (Stonecrop) needs ~975 GDD — county provides 2,262 GDD Excellent fit

Sedum (Stonecrop) Planting Timeline — Castleton, IL

Sedum (Stonecrop) Planting Calendar

Activity When Date Range
Start Indoors February 17 Feb 17 – Mar 3
Transplant Outdoors May 5 May 5 – May 19
Bloom September 1 Sep 1 – Nov 10

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

174 days in Stark County

Growing Tips for Sedum (Stonecrop) in Castleton

Direct sow Sedum (Stonecrop) outdoors after April 21 in Stark County when soil has warmed and frost danger has passed.

General growing tips

Plant divisions or container plants in spring after frost danger passes, or in early fall. Excellent drainage is the primary requirement — upright border sedums will rot in wet, heavy soils over winter. Lean soil actually improves performance; avoid over-fertilizing which causes floppy stems. Tall cultivars (Autumn Joy, Matrona) may need light staking in rich soil. Divide every 3–4 years in spring when centers become sparse. Deadhead selectively — leaving seed heads through winter extends ornamental interest and feeds goldfinches. Very low water requirement once established. Year 2+ plants reach full clump size and peak bloom display.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

When should I plant Sedum (Stonecrop) in Castleton, IL?

In Castleton, IL, plant Sedum (Stonecrop) after the last frost (around April 21) and before the first frost (around October 12). Best results when soil holds above 50°F.

What growing zone is Castleton, IL for Sedum (Stonecrop)?

Castleton sits in USDA Zone 5b. Sedum (Stonecrop) grows reliably in zones 3a through 10b, so it's a good fit here.

Can Sedum (Stonecrop) grow in Castleton's climate?

Yes — Sedum (Stonecrop) grows well in Castleton's temperate climate. Castleton averages a 174-day frost-free season, with last frost around April 21 and first frost around October 12.

🌱

Your Stark County Garden Planner — Free

A 22-page printable planner built for Stark County (Zone 5b). 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 Stark County, IL. Local conditions may vary. Last updated: July 2026.