When to plant Sedum (Stonecrop) in Custer County, MT
Plant Sedum (Stonecrop) in Custer County, between May 28 and June 11 — the only viable window. Zone 4b's short season (136 frost-free days) rules out a fall crop.
When to Plant Sedum (Stonecrop) in Custer County, MT
Custer County, Montana gardeners: here's your June plan
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.
To set up a strong July, finish these tasks
- Starting indoors: sedum (stonecrop)
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, Montana is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is September 27, giving you a growing season of approximately 136 days.
At an elevation of 5,983 feet, Custer County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Sedum (Stonecrop) to ensure they mature before fall.
Custer County Soil Profile
Soil Type
Loam
Soil pH
6.5-8.1
Drainage
Well Drained
Sedum (Stonecrop) Planting Risk Windows
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 (6.5–8.1) 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 (2.7%). Annual compost additions will help Sedum (Stonecrop).
How to Plant Sedum (Stonecrop)
Succession Planting Sedum (Stonecrop)
Sow every 6.9 weeks. Last sowing by Jun 29 to harvest before frost.
Sedum (Stonecrop) Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | — | 2.6" | 0" | ❄️ Dormant |
| May | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| Jul | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.9" | 0" | ❄️ Dormant |
| Dec | — | 1.4" | 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) Planting Timeline — Custer County, MT
Sedum (Stonecrop) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 5 | Mar 5 – Mar 19 |
| Transplant Outdoors | May 28 | May 28 – Jun 11 |
| Bloom | October 1 | Oct 1 – Nov 26 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | — |
| 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: too_alkaline
🗺️ USDA Zone
Zone 4b
📆 Growing Season
136 days in Custer County
Growing Tips for Sedum (Stonecrop) in Custer County
Direct sow Sedum (Stonecrop) outdoors after May 14 in Custer County when soil has warmed and frost danger has passed.
Custer County receives only 24" 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 →
Sedum (Stonecrop) in Other Locations
Frequently Asked Questions
When should I plant Sedum (Stonecrop) in Custer County, MT?
Custer County is in Zone 4b with an average last frost of May 14. Plan your Sedum (Stonecrop) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Custer County, MT?
Custer County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 14 and first fall frost is September 27.
When should I plant Sedum (Stonecrop) in Custer County, MT?
In Custer County, MT, plant Sedum (Stonecrop) after the last frost (around May 14) and before the first frost (around September 27). Best results when soil holds above 50°F.
What growing zone is Custer County, MT for Sedum (Stonecrop)?
Custer County sits in USDA Zone 4b. 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 136-day frost-free season, with last frost around May 14 and first frost around September 27.
Your Custer County Garden Planner — Free
A 22-page printable planner built for Custer County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.