When to Plant Peppers in Clackamas County, OR
Clackamas County, Oregon gardeners: here's your May plan
May is a pivotal month for Clackamas County, Oregon gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Fire up the seed-starting tray: peppers
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
Looking ahead to June
- First harvests: peppers
Sweet peppers are warm-season crops producing fruits in a rainbow of colors. They turn from green to red, yellow, or orange as they ripen, increasing in sweetness.
Clackamas County, Oregon is in USDA Zone 9a. The average last spring frost is April 14 and the first fall frost is October 28, giving you a growing season of approximately 197 days.
At an elevation of 199 feet, Clackamas County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Peppers during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Peppers root diseases.
Clackamas County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.3
Drainage
Well Drained
Plant 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 Clackamas County
How your county's soil matches Peppers's growing requirements.
Soil pH
Your soil pH (5.7–6.3) overlaps with Peppers's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Clackamas County is excellent for Peppers — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.7%) — Peppers will thrive.
How to Plant Peppers
Succession Planting Peppers
Sow every 6.9 weeks. Last sowing by Jul 30 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Peppers
Peppers needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.
| Month | Peppers Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.3" | 0" | ❄️ Dormant |
| Feb | — | 5.3" | 0" | ❄️ Dormant |
| Mar | — | 4.8" | 0" | ❄️ Dormant |
| Apr | 4.8" | 4" | 0.8" | 💧 Light watering |
| May | 4.8" | 3.3" | 1.5" | 💧 Light watering |
| Jun | 4.8" | 2.1" | 2.7" | 🚿 Regular watering |
| Jul | 4.8" | 0.8" | 4" | 🚿 Regular watering |
| Aug | 4.8" | 1" | 3.8" | 🚿 Regular watering |
| Sep | 4.8" | 2.2" | 2.6" | 🚿 Regular watering |
| Oct | 4.8" | 4.7" | 0.1" | 💧 Light watering |
| Nov | — | 8.2" | 0" | ❄️ Dormant |
| Dec | — | 8.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Clackamas County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Peppers 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.
Peppers Planting Timeline — Clackamas County, OR
Peppers Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 14 | Apr 14 – May 5 |
| Harvest | June 23 | Jun 23 – Sep 1 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.1"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
197 days in Clackamas County
Growing Tips for Peppers in Clackamas County
Direct sow Peppers outdoors after April 14 in Clackamas County when soil has warmed and frost danger has passed.
Common pests for Peppers in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 8-10 weeks before last frost. Transplant when nighttime temperatures stay above 55F. Avoid high-nitrogen fertilizers which promote leaves over fruit.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 300 ft for purity. Hot and sweet peppers can cross-pollinate.
Peppers in Other Locations
Frequently Asked Questions
When should I plant Peppers in Clackamas County, OR?
Clackamas County is in Zone 9a with an average last frost of April 14. Plan your Peppers planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clackamas County, OR?
Clackamas County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 14 and first fall frost is October 28.
Your Clackamas County Garden Planner — Free
A 24-page printable planner built for Clackamas 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.