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When to plant Sedum (Stonecrop) in Plymouth County County,

Plymouth County County's short 159-day growing season means one Sedum (Stonecrop) planting between May 14 and May 28. No fall crop in Zone 5a.

When to Plant Sedum (Stonecrop) in Plymouth County, IA

Plymouth County, Iowa Zone 5a June

Your June gardening checklist

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

Avg. last frost April 30
Avg. first frost October 6
Soil temp (4") 63°F
Watering Low
Pest pressure High
Daylight 15.1 hrs
Get ahead of July
  • Starting indoors: sedum (stonecrop)

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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.

Plymouth County, Iowa is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 6, giving you a growing season of approximately 159 days.

At an elevation of 1,392 feet, Plymouth County receives approximately 38 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°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
Plymouth County, IA (Zone 5a) Moderate season
159 days
Last Spring Frost April 30
159 growing days
First Fall Frost October 6

Plymouth County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

Drainage

Well Drained

Sedum (Stonecrop) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 17 Transplant: May 5 🌸 Bloom: Sep 1 – Nov 3
Recommended (50%) ✗ May not fit
Start indoors: Feb 26 Transplant: May 14 🌸 Bloom: Sep 10 – Nov 12
Safe Start (90%) ✗ May not fit
Start indoors: Mar 12 Transplant: May 28 🌸 Bloom: Sep 24 – Nov 26

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 Plymouth County

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

Soil pH

Your soil pH (6.0–7.2) overlaps with Sedum (Stonecrop)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — 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 159-day season

Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.

Sedum (Stonecrop) Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 2.2" 3.9" 0" ✅ Rainfall sufficient
May 2.2" 4.8" 0" ✅ Rainfall sufficient
Jun 2.2" 4.2" 0" ✅ Rainfall sufficient
Jul 2.2" 4.4" 0" ✅ Rainfall sufficient
Aug 2.2" 4.3" 0" ✅ Rainfall sufficient
Sep 2.2" 3.4" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2.8" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Plymouth 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 ~919 GDD — county provides 1,947 GDD Excellent fit

Sedum (Stonecrop) Planting Timeline — Plymouth County, IA

Sedum (Stonecrop) Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors May 14 May 14 – May 28
Bloom September 10 Sep 10 – Nov 12

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: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

159 days in Plymouth County

Growing Tips for Sedum (Stonecrop) in Plymouth County

Direct sow Sedum (Stonecrop) outdoors after April 30 in Plymouth 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 →

Frequently Asked Questions

When should I plant Sedum (Stonecrop) in Plymouth County, IA?

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

What planting zone is Plymouth County, IA?

Plymouth County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 6.

When should I plant Sedum (Stonecrop) in Plymouth County County, ?

In Plymouth County County, , plant Sedum (Stonecrop) after the last frost (around April 30) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Plymouth County County, for Sedum (Stonecrop)?

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

Can Sedum (Stonecrop) grow in Plymouth County County's climate?

Yes — Sedum (Stonecrop) grows well in Plymouth County County's temperate climate. Plymouth County County averages a 159-day frost-free season, with last frost around April 30 and first frost around October 6.

🌱

Your Plymouth County Garden Planner — Free

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

Sources & credits

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