When to plant Sedum (Stonecrop) in Flathead County County,
Flathead County County's 99-day season only supports one Sedum (Stonecrop) planting per year. Sow between June 17 and July 1 for the best chance at full maturity before September 10.
When to Plant Sedum (Stonecrop) in Flathead County, MT
Flathead County, Montana gardeners: here's your June plan
Welcome to June in Zone 5a. These are the moves that will have the biggest impact on your growing season.
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Move sedum (stonecrop) into the garden
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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.
Flathead County, Montana is in USDA Zone 5a. The average last spring frost is June 3 and the first fall frost is September 10, giving you a growing season of approximately 99 days.
At an elevation of 6,233 feet, Flathead County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Sedum (Stonecrop) during the growing season.
Flathead County Soil Profile
Soil Type
Loam
Soil pH
6.6-8.4
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 Flathead County
How your county's soil matches Sedum (Stonecrop)'s growing requirements.
Soil pH
Your soil pH (6.6–8.4) 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 Flathead County is excellent for Sedum (Stonecrop) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Sedum (Stonecrop).
How to Plant Sedum (Stonecrop)
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.6" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | — | 2.7" | 0" | ❄️ Dormant |
| Jun | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Jul | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Aug | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Sep | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Flathead 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 — Flathead County, MT
Sedum (Stonecrop) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 1 | Apr 1 – Apr 15 |
| Transplant Outdoors | June 17 | Jun 17 – Jul 1 |
| Bloom | October 14 | Oct 14 – Dec 16 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
99 days in Flathead County
Growing Tips for Sedum (Stonecrop) in Flathead County
Direct sow Sedum (Stonecrop) outdoors after June 03 in Flathead County when soil has warmed and frost danger has passed.
Your 99.0-day growing season in Flathead County is tight for Sedum (Stonecrop) (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.
Flathead County receives only 21" 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 Flathead County, MT?
Flathead County is in Zone 5a with an average last frost of June 3. Plan your Sedum (Stonecrop) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Flathead County, MT?
Flathead County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 3 and first fall frost is September 10.
When should I plant Sedum (Stonecrop) in Flathead County, ?
In Flathead County, , plant Sedum (Stonecrop) after the last frost (around June 3) and before the first frost (around September 10). Best results when soil holds above 50°F.
What growing zone is Flathead County, for Sedum (Stonecrop)?
Flathead 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 Flathead County's climate?
Yes — Sedum (Stonecrop) grows well in Flathead County's temperate climate. Flathead County averages a 99-day frost-free season, with last frost around June 3 and first frost around September 10.
Your Flathead County Garden Planner — Free
A 22-page printable planner built for Flathead 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.