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When to Plant Jostaberry in Grays Harbor County, WA

Grays Harbor County, Washington Zone 8b May

Your May gardening checklist

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

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. Transplant jostaberry outside

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

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Jostaberry is a thornless hybrid of black currant and gooseberry, producing medium-sized, dark berries with a complex, tart-sweet flavor. It is vigorous and disease-resistant.

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 Jostaberry 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
Transplant: May 5
Recommended (50%) ✓ Fits season
Transplant: May 18
Safe Start (90%) ✓ Fits season
Transplant: Jun 2

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 Jostaberry's growing requirements.

Soil pH

Your soil pH (5.5–6.7) overlaps with Jostaberry's range (6.0–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Jostaberry

48"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 120 gal / 100 sq ft

Monthly Watering Guide for Jostaberry

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

Month Jostaberry Needs Rainfall You Supplement Action
Jan 5.9" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 2.2" 2.1" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.8" 3.5" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 4.3" 3.5" 0.8" 💧 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.

Jostaberry 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.

Jostaberry needs ~14,600 GDD — county provides 2,864 GDD May not mature

Jostaberry Planting Timeline — Grays Harbor County, WA

Jostaberry Planting Calendar

Activity When Date Range
Transplant Outdoors May 18 May 18 – Jun 1

· 48" apart · Rows 72" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 6–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

179 days in Grays Harbor County

Growing Tips for Jostaberry in Grays Harbor County

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

Your 179.0-day growing season in Grays Harbor County is tight for Jostaberry (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant in rich, well-drained soil. No special pruning required beyond removing old wood. Self-fertile but yields improve with a second bush. Berries ripen midsummer.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

Grays Harbor County is in Zone 8b with an average last frost of April 27. Plan your Jostaberry 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.

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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.

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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 Grays Harbor County, WA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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