When to Plant Sedum (Stonecrop) in Harper County, OK
June in Harper County, Oklahoma — your action list
A quick June briefing for Harper County, Oklahoma gardeners — what's urgent, what's next, and what can wait.
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Indoor seed-starting week for sedum (stonecrop)
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
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.
Harper County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 18, giving you a growing season of approximately 186 days.
At an elevation of 861 feet, Harper County receives approximately 21.5 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Sedum (Stonecrop) during the growing season.
Harper County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.2
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 Harper County
How your county's soil matches Sedum (Stonecrop)'s growing requirements.
Soil pH
Your soil pH (6.4–7.2) overlaps with Sedum (Stonecrop)'s range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Harper County is excellent for Sedum (Stonecrop) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.6%). Annual compost additions will help Sedum (Stonecrop).
How to Plant Sedum (Stonecrop)
Succession Planting Sedum (Stonecrop)
Sow every 6.9 weeks. Last sowing by Jul 20 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 | — | 0.5" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2" | 0.2" | 💧 Light watering |
| Oct | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Nov | — | 0.7" | 0" | ❄️ Dormant |
| Dec | — | 0.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Harper 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 — Harper County, OK
Sedum (Stonecrop) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 11 | Feb 11 – Feb 25 |
| Transplant Outdoors | April 22 | Apr 22 – May 6 |
| Bloom | August 12 | Aug 12 – Nov 4 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
186 days in Harper County
Growing Tips for Sedum (Stonecrop) in Harper County
Direct sow Sedum (Stonecrop) outdoors after April 15 in Harper County when soil has warmed and frost danger has passed.
Harper County receives only 22" 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 Harper County, OK?
Harper County is in Zone 7a with an average last frost of April 15. Plan your Sedum (Stonecrop) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harper County, OK?
Harper County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 18.
Your Harper County Garden Planner — Free
A 22-page printable planner built for Harper County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.