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

Plant Sedum (Stonecrop) in Summit County during the brief June 30–July 14 window. With 80 frost-free days, fall plantings can't mature before September 4.

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

Summit County, Colorado Zone 5a June

June to-do list for Summit County, Colorado

Here's what deserves your attention in Summit County, Colorado this month. Everything below is tailored to Zone 5a and timed around your local frost dates.

Avg. last frost June 16
Avg. first frost September 4
Soil temp (4") 45°F
Watering High
Pest pressure High
Daylight 14.8 hrs
  1. Transplant sedum (stonecrop) outside

    Frost risk is low now in Summit County, Colorado. If you've been covering beds overnight, you can stop.

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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.

Summit County, Colorado is in USDA Zone 5a. The average last spring frost is June 16 and the first fall frost is September 4, giving you a growing season of approximately 80 days.

At an elevation of 7,005 feet, Summit County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Sedum (Stonecrop) to ensure they mature before fall. 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
Summit County, CO (Zone 5a) Very short season
80 days
Last Spring Frost June 16
80 growing days
First Fall Frost September 4

Summit County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Sedum (Stonecrop) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 8 Transplant: Jun 24 🌸 Bloom: Oct 21 – Dec 23
Recommended (50%) ✗ May not fit
Start indoors: Apr 14 Transplant: Jun 30 🌸 Bloom: Oct 27 – Dec 29
Safe Start (90%) ✓ Fits season (255 days to spare)
Start indoors: Apr 24 Transplant: Jul 10 🌸 Bloom: Nov 6 – Jan 8

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 Summit County

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

Soil pH

Your soil pH (6.8–8.0) 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 Summit County is excellent for Sedum (Stonecrop) — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sedum (Stonecrop).

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Sedum (Stonecrop).

How to Plant Sedum (Stonecrop)

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

Sedum (Stonecrop) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 1.4" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 1.8" 0" ❄️ Dormant
Jun 2.2" 1.3" 0.9" 💧 Light watering
Jul 2.2" 1.5" 0.7" 💧 Light watering
Aug 2.2" 1.9" 0.3" 💧 Light watering
Sep 2.2" 1.3" 0.9" 💧 Light watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Summit 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 ~806 GDD — county provides 860 GDD Good fit

Sedum (Stonecrop) Planting Timeline — Summit County, CO

Sedum (Stonecrop) Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors June 30 Jun 30 – Jul 14
Bloom October 27 Oct 27 – Dec 29

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May
June Transplant Outdoors
July Transplant Outdoors
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 5a

📆 Growing Season

80 days in Summit County

Growing Tips for Sedum (Stonecrop) in Summit County

Direct sow Sedum (Stonecrop) outdoors after June 16 in Summit County when soil has warmed and frost danger has passed.

Your 80.0-day growing season in Summit County is tight for Sedum (Stonecrop) (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

Summit 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 Summit County, CO?

Summit County is in Zone 5a with an average last frost of June 16. Plan your Sedum (Stonecrop) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Summit County, CO?

Summit County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 4.

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

In Summit County, CO, plant Sedum (Stonecrop) after the last frost (around June 16) and before the first frost (around September 4). Best results when soil holds above 50°F.

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

Summit 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 Summit County's climate?

Yes — Sedum (Stonecrop) grows well in Summit County's temperate climate. Summit County averages a 80-day frost-free season, with last frost around June 16 and first frost around September 4.

🌱

Your Summit County Garden Planner — Free

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.