Blog

When to Plant Hot Peppers in Washington County, OR

Washington County, Oregon Zone 8b May

May in Washington County, Oregon — your action list

May is a pivotal month for Washington County, Oregon gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 15
Avg. first frost October 27
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.7 hrs
A few tasks this May that'll pay off in June
  • Starting indoors: hot peppers

Instant PDF download. No spam, unsubscribe any time.

Hot peppers range from mildly spicy jalapenos to scorching superhots. They require long, warm growing seasons and produce capsaicin that gives them their heat.

Washington County, Oregon is in USDA Zone 8b. The average last spring frost is April 15 and the first fall frost is October 27, giving you a growing season of approximately 195 days.

At an elevation of 352 feet, Washington County receives approximately 47.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Hot Peppers during the growing season.

Washington County, OR (Zone 8b) Moderate season
195 days
Last Spring Frost April 15
195 growing days
First Fall Frost October 27

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Feb 4 Transplant: Apr 22 🍅 Harvest: Jul 1 – Oct 7
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Feb 11 Transplant: Apr 29 🍅 Harvest: Jul 8 – Oct 14
Safe Start (90%) ✓ Fits season (14 days to spare)
Start indoors: Mar 6 Transplant: May 22 🍅 Harvest: Jul 31 – Nov 6

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 Washington County

How your county's soil matches Hot Peppers's growing requirements.

Soil pH

Your soil pH (5.8–6.4) overlaps with Hot Peppers's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Washington County is excellent for Hot Peppers — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) — Hot Peppers will thrive.

How to Plant Hot Peppers

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Hot Peppers

3
successive plantings in your 195-day season

Sow every 8 weeks. Last sowing by Jun 29 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Hot Peppers

Hot Peppers needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Hot Peppers Needs Rainfall You Supplement Action
Jan 7.4" 0" ❄️ Dormant
Feb 5.7" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.9" 3.4" 🚿 Regular watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 7.3" 0" ❄️ Dormant
Dec 8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Washington County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Hot 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.

Hot Peppers needs ~1,306 GDD — county provides 2,681 GDD Excellent fit

Hot Peppers Planting Timeline — Washington County, OR

Hot Peppers Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 22 Apr 22 – May 13
Harvest July 8 Jul 8 – Oct 14

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

195 days in Washington County

Growing Tips for Hot Peppers in Washington County

Direct sow Hot Peppers outdoors after April 15 in Washington County when soil has warmed and frost danger has passed.

Common pests for Hot 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 10-12 weeks before last frost as they germinate slowly. Use heat mats to maintain 80-85F soil temperature for germination. Stress plants slightly by reducing water to increase heat levels.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hot Peppers in Washington County, OR?

Washington County is in Zone 8b with an average last frost of April 15. Plan your Hot Peppers planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, OR?

Washington County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 15 and first fall frost is October 27.

🌱

Your Washington County Garden Planner — Free

A 24-page printable planner built for Washington County (Zone 8b). 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 Washington County, OR. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.