Blog

When to Plant Cucumber in Grays Harbor County, WA

Grays Harbor County, Washington Zone 8b May

Your May planting checklist for Grays Harbor County, Washington

Your Grays Harbor County, Washington garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 27
Avg. first frost October 23
Soil temp (4") 69°F
Watering High
Pest pressure High
Daylight 14.9 hrs
  1. Move cucumber into the garden

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Sow cucumber where they'll grow

    These tolerate cool soil, so you're not gambling by sowing now.

  3. Time to start cucumber inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Instant PDF download. No spam, unsubscribe any time.

Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

Grays Harbor County, Washington is in USDA Zone 8b. The average last spring frost is April 27 and the first fall frost is October 23, giving you a growing season of approximately 179 days.

At an elevation of 65 feet, Grays Harbor County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Cucumber during the growing season.

Grays Harbor County, WA (Zone 8b) Moderate season
179 days
Last Spring Frost April 27
179 growing days
First Fall Frost October 23

Grays Harbor County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Mar 17 Transplant: Apr 28 🍅 Harvest: Jun 23 – Aug 18
Recommended (50%) ✓ Fits season (53 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jul 6 – Aug 31
Safe Start (90%) ✓ Fits season (67 days to spare)
Start indoors: Apr 14 Transplant: May 26 🍅 Harvest: Jul 21 – Sep 15

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 Grays Harbor County

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

Soil pH

Your soil pH (5.5–6.7) overlaps with Cucumber's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Cucumber

0.5"
Planting Depth
24"
Between Plants
48"
Between Rows

Succession Planting Cucumber

4
successive plantings in your 179-day season

Sow every 5.7 weeks. Last sowing by Aug 14 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 917 gal / 100 sq ft

Monthly Watering Guide for Cucumber

Cucumber needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Cucumber Needs Rainfall You Supplement Action
Jan 5.9" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 6.5" 3.3" 3.2" 💧 Light watering
May 6.5" 2.2" 4.3" 🚿 Regular watering
Jun 6.5" 1.7" 4.8" 🚿 Regular watering
Jul 6.5" 0.6" 5.9" 🚿 Regular watering
Aug 6.5" 0.8" 5.7" 🚿 Regular watering
Sep 6.5" 1.5" 5" 🚿 Regular watering
Oct 6.5" 3.5" 3" 💧 Light watering
Nov 5.9" 0" ❄️ Dormant
Dec 5.7" 0" ❄️ Dormant

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

Cucumber 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.

Cucumber needs ~960 GDD — county provides 2,864 GDD Excellent fit

Cucumber Planting Timeline — Grays Harbor County, WA

Cucumber Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 4 May 4 – May 25
Harvest July 6 Jul 6 – Aug 31

Plant 0.5" deep · 24" apart · Rows 48" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

179 days in Grays Harbor County

Growing Tips for Cucumber in Grays Harbor County

Direct sow Cucumber outdoors after April 27 in Grays Harbor County when soil has warmed and frost danger has passed.

Common pests for Cucumber in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cucumber in Grays Harbor County, WA?

Grays Harbor County is in Zone 8b with an average last frost of April 27. Plan your Cucumber planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grays Harbor County, WA?

Grays Harbor County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 27 and first fall frost is October 23.

🌱

Your Grays Harbor County Garden Planner — Free

A 24-page printable planner built for Grays Harbor 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 Grays Harbor County, WA. 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.