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When to Plant Cranberries in Benton County, WA

Benton County, Washington Zone 7b May

May in Benton County, Washington — your action list

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

Avg. last frost April 3
Avg. first frost October 27
Soil temp (4") 62°F
Watering High
Pest pressure Moderate
Daylight 14.8 hrs

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Cranberries are low-growing, vine-like shrubs that produce tart red berries in fall. They grow in acidic, boggy conditions and are surprisingly easy to cultivate.

Benton County, Washington is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is October 27, giving you a growing season of approximately 207 days.

At an elevation of 2,633 feet, Benton County receives approximately 22.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Cranberries during the growing season.

Benton County, WA (Zone 7b) Long season
207 days
Last Spring Frost April 3
207 growing days
First Fall Frost October 27

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 14
Recommended (50%) ✓ Fits season
Transplant: Apr 24
Safe Start (90%) ✓ Fits season
Transplant: May 11

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 Benton County

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

Soil pH

Your soil pH (5.5–6.3) is more alkaline than Cranberries prefers (4.0–5.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Cranberries will thrive.

How to Plant Cranberries

36"
Between Plants
48"
Between Rows

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,922 gal / 100 sq ft

Monthly Watering Guide for Cranberries

Cranberries 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 Cranberries Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 6.5" 1.5" 5" 🚿 Regular watering
May 6.5" 1.4" 5.1" 🚿 Regular watering
Jun 6.5" 0.9" 5.6" 🚿 Regular watering
Jul 6.5" 0.4" 6.1" 🚿 Regular watering
Aug 6.5" 0.4" 6.1" 🚿 Regular watering
Sep 6.5" 0.8" 5.7" 🚿 Regular watering
Oct 6.5" 2" 4.5" 🚿 Regular watering
Nov 3.7" 0" ❄️ Dormant
Dec 3.5" 0" ❄️ Dormant

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

Cranberries 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.

Cranberries needs ~14,600 GDD — county provides 3,312 GDD May not mature

Cranberries Planting Timeline — Benton County, WA

Cranberries Planting Calendar

Activity When Date Range
Transplant Outdoors April 24 Apr 24 – May 8

· 36" apart · Rows 48" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 4–5.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

207 days in Benton County

Growing Tips for Cranberries in Benton County

Direct sow Cranberries outdoors after April 03 in Benton County when soil has warmed and frost danger has passed.

Your 207.0-day growing season in Benton County is tight for Cranberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

Benton County receives only 22" of rain annually. Cranberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Create an acidic, consistently moist bed with peat moss. Cranberries do not need to be flooded to grow; flooding is only used for commercial harvesting. Mulch with sand in early spring.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cranberries in Benton County, WA?

Benton County is in Zone 7b with an average last frost of April 3. Plan your Cranberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Benton County, WA?

Benton County, Washington is in USDA Hardiness Zone 7b. The average last spring frost is April 3 and first fall frost is October 27.

🌱

Your Benton County Garden Planner — Free

A 24-page printable planner built for Benton County (Zone 7b). 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 Benton 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.