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When to Plant Fava Beans in Enumclaw, WA

King County, Washington Zone 9a July

Your July planting checklist for King County, Washington

We've pulled the most time-sensitive tasks for King County, Washington this July and put them front and centre. Tackle them in order.

Avg. last frost April 7
Avg. first frost October 30
Soil temp (4") 89°F
Watering Critical
Pest pressure High
Daylight 15.4 hrs

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Fava beans are a cool-season legume with large, meaty beans inside thick pods. They fix nitrogen in the soil and are one of the oldest cultivated crops.

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 Fava Beans 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

Fava Beans Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Feb 24 Transplant: Mar 24 🍅 Harvest: Jun 9 – Jul 21
Recommended (50%) ✓ Fits season (87 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Jun 23 – Aug 4
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Apr 22 Transplant: May 20 🍅 Harvest: Aug 5 – Sep 16

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 Fava Beans's growing requirements.

Soil pH

Your soil pH (5.7–6.4) overlaps with Fava Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Fava Beans

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

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

Succession Planting Fava Beans

3
successive plantings in your 206-day season

Sow every 8.6 weeks. Last sowing by Jul 22 to harvest before frost.

For a dedicated fall crop, sow by Sep 04.

Fava Beans Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 428 gal / 100 sq ft

Monthly Watering Guide for Fava Beans

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

Month Fava Beans Needs Rainfall You Supplement Action
Jan 5.9" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 2" 2.3" 🚿 Regular watering
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.7" 3.6" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
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.

Fava Beans 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.

Fava Beans needs ~1,466 GDD — county provides 3,450 GDD Excellent fit

Fava Beans Planting Timeline — Enumclaw, WA

Fava Beans 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 23 Jun 23 – Aug 4
Fall Sowing September 4 Sep 4 – Sep 18

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

206 days in King County

Growing Tips for Fava Beans in Enumclaw

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

Common pests for Fava Beans 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. Pinch growing tips when pods begin to form to redirect energy and reduce aphid problems. Stake tall varieties.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

🌱

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.

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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 King County, WA. Local conditions may vary. Last updated: July 2026.