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When to plant Sedum (Stonecrop) in Custer County, CO

In Custer County, Sedum (Stonecrop) is a single-season spring crop — there's no second fall window. Plant June 6–June 20 for an 60–90-day harvest, finishing well before the September 25 first frost.

When to Plant Sedum (Stonecrop) in Custer County, CO

Custer County, Colorado Zone 5b June

June in the garden — Custer County, Colorado

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 23
Avg. first frost September 25
Soil temp (4") 44°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
  1. Transplant sedum (stonecrop) outside

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

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

Custer County, Colorado is in USDA Zone 5b. The average last spring frost is May 23 and the first fall frost is September 25, giving you a growing season of approximately 125 days.

At an elevation of 8,115 feet, Custer County receives approximately 18.1 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Sedum (Stonecrop) during the growing season. With low rainfall, drip irrigation is essential for growing Sedum (Stonecrop) successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Fall Pollinator-friendly Deer-resistant Good for cutting
Custer County, CO (Zone 5b) Short season
125 days
Last Spring Frost May 23
125 growing days
First Fall Frost September 25

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Sedum (Stonecrop) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 9 Transplant: May 25 🌸 Bloom: Sep 21 – Nov 30
Recommended (50%) ✗ May not fit
Start indoors: Mar 21 Transplant: Jun 6 🌸 Bloom: Oct 3 – Dec 12
Safe Start (90%) ✓ Fits season (282 days to spare)
Start indoors: Apr 13 Transplant: Jun 29 🌸 Bloom: Oct 26 – Jan 4

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 Custer County

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

Soil pH

Your soil pH (6.5–7.8) is more alkaline than Sedum (Stonecrop) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Sedum (Stonecrop).

How to Plant Sedum (Stonecrop)

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

Succession Planting Sedum (Stonecrop)

2
successive plantings in your 125-day season

Sow every 6.9 weeks. Last sowing by Jun 27 to harvest before frost.

Sedum (Stonecrop) Water Budget

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

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.2" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 2.2" 2.3" 0" ✅ Rainfall sufficient
Jun 2.2" 1.2" 1" 💧 Light watering
Jul 2.2" 1.4" 0.8" 💧 Light watering
Aug 2.2" 2.1" 0.1" 💧 Light watering
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Custer 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 ~1,088 GDD — county provides 1,812 GDD Excellent fit

Sedum (Stonecrop) Planting Timeline — Custer County, CO

Sedum (Stonecrop) Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors June 6 Jun 6 – Jun 20
Bloom October 3 Oct 3 – Dec 12

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

Month-by-Month Timeline

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

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: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

125 days in Custer County

Growing Tips for Sedum (Stonecrop) in Custer County

Direct sow Sedum (Stonecrop) outdoors after May 23 in Custer County when soil has warmed and frost danger has passed.

Custer County receives only 18" of rain annually. Sedum (Stonecrop) needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Custer County, CO?

Custer County is in Zone 5b with an average last frost of May 23. Plan your Sedum (Stonecrop) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, CO?

Custer County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 23 and first fall frost is September 25.

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

In Custer County, CO, plant Sedum (Stonecrop) after the last frost (around May 23) and before the first frost (around September 25). Best results when soil holds above 50°F.

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

Custer County 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 Custer County's climate?

Yes — Sedum (Stonecrop) grows well in Custer County's temperate climate. Custer County averages a 125-day frost-free season, with last frost around May 23 and first frost around September 25.

🌱

Your Custer County Garden Planner — Free

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

Sources & credits

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