Blog

When to Plant Sedum (Stonecrop) in Gresham, OR

Multnomah County, Oregon Zone 9a August

Top priorities for Multnomah County, Oregon gardeners in August

Each item below is timed to Multnomah County, Oregon's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 14
Avg. first frost October 27
Soil temp (4") 91°F
Watering Critical
Pest pressure High
Daylight 13.9 hrs
  1. Start harvesting sedum (stonecrop)

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Looking ahead to September
  • First harvests: sedum (stonecrop)

Instant PDF download. No spam, unsubscribe any time.

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.

Gresham, Oregon is in USDA Zone 9a. The average last spring frost is April 14 and the first fall frost is October 27, giving you a growing season of approximately 196 days.

At an elevation of 357 feet, Multnomah County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Sedum (Stonecrop) to ensure they mature before fall.

Perennial Blooms in Fall Pollinator-friendly Deer-resistant Good for cutting
Gresham, OR (Zone 9a) Moderate season
196 days
Last Spring Frost April 14
196 growing days
First Fall Frost October 27

Gresham Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.3

Drainage

Well Drained

Sedum (Stonecrop) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Start indoors: Feb 11 Transplant: Mar 25 🌸 Bloom: Jul 15 – Sep 23
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Feb 17 Transplant: Mar 31 🌸 Bloom: Jul 21 – Sep 29
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Mar 14 Transplant: Apr 25 🌸 Bloom: Aug 15 – Oct 24

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 Gresham

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

Soil pH

Your soil pH (5.8–6.3) overlaps with Sedum (Stonecrop)'s range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Multnomah 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 excellent (4.5%) — Sedum (Stonecrop) will thrive.

How to Plant Sedum (Stonecrop)

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

Succession Planting Sedum (Stonecrop)

3
successive plantings in your 196-day season

Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.

Sedum (Stonecrop) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 5.8" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 2.2" 2.3" 0" ✅ Rainfall sufficient
May 2.2" 2.3" 0" ✅ Rainfall sufficient
Jun 2.2" 1.3" 0.9" 💧 Light watering
Jul 2.2" 0.6" 1.6" 🚿 Regular watering
Aug 2.2" 0.7" 1.5" 🚿 Regular watering
Sep 2.2" 1.6" 0.6" 💧 Light watering
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 6" 0" ❄️ Dormant
Dec 4.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Multnomah 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 ~975 GDD — county provides 2,548 GDD Excellent fit

Sedum (Stonecrop) Planting Timeline — Gresham, OR

Sedum (Stonecrop) Planting Calendar

Activity When Date Range
Start Indoors February 17 Feb 17 – Mar 3
Transplant Outdoors March 31 Mar 31 – Apr 14
Bloom July 21 Jul 21 – Sep 29

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9a

📆 Growing Season

196 days in Multnomah County

Growing Tips for Sedum (Stonecrop) in Gresham

Direct sow Sedum (Stonecrop) outdoors after April 14 in Multnomah 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 →

🌱

Your Multnomah County Garden Planner — Free

A 22-page printable planner built for Multnomah County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Multnomah County, OR. Local conditions may vary. Last updated: August 2026.