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When to Plant Peas in Enumclaw, WA

Peas
King County, Washington Zone 9a August

This month in King County, Washington

A quick August briefing for King County, Washington gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 7
Avg. first frost October 30
Soil temp (4") 90°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
Looking ahead to September
  • Fall sowing: peas

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Peas are a cool-season legume that fixes nitrogen in the soil. Garden peas are shelled, while snap and snow peas are eaten pod and all.

Enumclaw, Washington is in USDA Zone 9a. The average last spring frost is April 7 and the first fall frost is October 30, giving you a growing season of approximately 206 days.

At an elevation of 258 feet, King County receives approximately 37.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Peas during the growing season.

Enumclaw, WA (Zone 9a) Long season
206 days
Last Spring Frost April 7
206 growing days
First Fall Frost October 30

Enumclaw Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.4

Drainage

Well Drained

Peas Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Start indoors: Feb 24 Transplant: Mar 24 🍅 Harvest: May 19 – Jul 14
Recommended (50%) ✓ Fits season (94 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Jun 2 – Jul 28
Safe Start (90%) ✓ Fits season (73 days to spare)
Start indoors: Apr 22 Transplant: May 20 🍅 Harvest: Jul 15 – Sep 9

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 Enumclaw

How your county's soil matches Peas's growing requirements.

Soil pH

Your soil pH (5.7–6.4) overlaps with Peas's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.5%) — Peas will thrive.

How to Plant Peas

1"
Planting Depth
4"
Between Plants
18"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Peas

4
successive plantings in your 206-day season

Sow every 6.3 weeks. Last sowing by Aug 21 to harvest before frost.

For a dedicated fall crop, sow by Sep 04.

Peas Water Budget

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

Monthly Watering Guide for Peas

Peas needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Peas Needs Rainfall You Supplement Action
Jan 5.9" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 3" 2.9" 0.1" 💧 Light watering
May 3" 2" 1" 💧 Light watering
Jun 3" 1.3" 1.7" 🚿 Regular watering
Jul 3" 0.6" 2.4" 🚿 Regular watering
Aug 3" 0.7" 2.3" 🚿 Regular watering
Sep 3" 1.6" 1.4" 💧 Light watering
Oct 3" 3.4" 0" ✅ Rainfall sufficient
Nov 5.6" 0" ❄️ Dormant
Dec 5.7" 0" ❄️ Dormant

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

Peas 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.

Peas needs ~1,047 GDD — county provides 3,450 GDD Excellent fit

Peas Planting Timeline — Enumclaw, WA

Peas Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 17 Mar 17 – Apr 7
Harvest June 2 Jun 2 – Jul 28
Fall Sowing September 4 Sep 4 – Sep 18

Plant 1" deep · 4" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

206 days in King County

Growing Tips for Peas in Enumclaw

Direct sow Peas outdoors after April 07 in King County when soil has warmed and frost danger has passed.

Common pests for Peas in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow as early as soil can be worked in spring. Inoculate seeds with rhizobium for best nitrogen fixation. Provide trellising for climbing varieties.

Recommended Peas Varieties for Enumclaw

Heat-tolerant peas — plant very early or as fall crop

Wando (68d) Oregon Sugar Pod (60d)

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Peas Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let pods dry brown and papery on the vine.
Storage Store airtight; viable 3 years at 35°F, under 45% humidity.

Very easy to save. Self-pollinating means varieties stay true.

🌱

Your King County Garden Planner — Free

A 22-page printable planner built for King 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 King County, WA. Local conditions may vary. Last updated: August 2026.