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When to Plant Sedum (Stonecrop) in Harmon County, OK

Harmon County, Oklahoma Zone 7b June

Your June gardening checklist

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Harmon County, Oklahoma.

Avg. last frost March 31
Avg. first frost November 5
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.3 hrs
  1. Time to start sedum (stonecrop) inside

    You're about 20 weeks out from your last frost — the perfect window to get these germinating indoors.

A few tasks this June that'll pay off in July
  • First harvests: 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.

Harmon County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 5, giving you a growing season of approximately 219 days.

At an elevation of 993 feet, Harmon County receives approximately 34.4 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Sedum (Stonecrop) during the growing season.

Perennial Blooms in Fall Pollinator-friendly Deer-resistant Good for cutting
Harmon County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 31
219 growing days
First Fall Frost November 5
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Harmon County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Sedum (Stonecrop) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Jan 19 Transplant: Mar 30 🌸 Bloom: Jul 20 – Oct 12
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Jan 27 Transplant: Apr 7 🌸 Bloom: Jul 28 – Oct 20
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Feb 11 Transplant: Apr 22 🌸 Bloom: Aug 12 – Nov 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 Harmon County

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

Soil pH

Your soil pH (6.5–7.5) overlaps with Sedum (Stonecrop)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Sedum (Stonecrop) will thrive.

How to Plant Sedum (Stonecrop)

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

Succession Planting Sedum (Stonecrop)

4
successive plantings in your 219-day season

Sow every 6.9 weeks. Last sowing by Aug 07 to harvest before frost.

Sedum (Stonecrop) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 0.9" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.2" 2.3" 0" ✅ Rainfall sufficient
Apr 2.2" 3.7" 0" ✅ Rainfall sufficient
May 2.2" 5.1" 0" ✅ Rainfall sufficient
Jun 2.2" 5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4.8" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 2" 0.2" 💧 Light watering
Nov 2.2" 1.3" 0.9" 💧 Light watering
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Harmon 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 ~1,369 GDD — county provides 3,996 GDD Excellent fit

Sedum (Stonecrop) Planting Timeline — Harmon County, OK

Sedum (Stonecrop) Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 – Feb 10
Transplant Outdoors April 7 Apr 7 – Apr 21
Bloom July 28 Jul 28 – Oct 20

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 7b

📆 Growing Season

219 days in Harmon County

Growing Tips for Sedum (Stonecrop) in Harmon County

Direct sow Sedum (Stonecrop) outdoors after March 31 in Harmon County when soil has warmed and frost danger has passed.

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 Harmon County, OK?

Harmon County is in Zone 7b with an average last frost of March 31. Plan your Sedum (Stonecrop) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harmon County, OK?

Harmon County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 5.

🌱

Your Harmon County Garden Planner — Free

A 22-page printable planner built for Harmon County (Zone 7b). 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 Harmon County, OK. 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.