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When to Plant New Zealand Spinach in Benton County, WA

Benton County, Washington Zone 7b May

Benton County, Washington gardeners: here's your May plan

Welcome to May in Zone 7b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 3
Avg. first frost October 27
Soil temp (4") 62°F
Watering High
Pest pressure Moderate
Daylight 14.8 hrs
  1. Time to start new zealand spinach inside

    You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.

June prep starts now
  • First harvests: new zealand spinach

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New Zealand spinach is a heat-tolerant ground-cover plant with thick, triangular leaves that taste similar to true spinach. It thrives in hot weather when regular spinach bolts.

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 New Zealand Spinach 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 (114 days to spare)
Start indoors: Feb 3 Transplant: Apr 7 🍅 Harvest: Jun 2 – Jun 30
Recommended (50%) ✓ Fits season (109 days to spare)
Start indoors: Feb 13 Transplant: Apr 17 🍅 Harvest: Jun 12 – Jul 10
Safe Start (90%) ✓ Fits season (106 days to spare)
Start indoors: Mar 2 Transplant: May 4 🍅 Harvest: Jun 29 – Jul 27

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 New Zealand Spinach's growing requirements.

Soil pH

Your soil pH (5.5–6.3) is more acidic than New Zealand Spinach prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — New Zealand Spinach will thrive.

How to Plant New Zealand Spinach

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Succession Planting New Zealand Spinach

4
successive plantings in your 207-day season

Sow every 6.3 weeks. Last sowing by Aug 18 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,001 gal / 100 sq ft

Monthly Watering Guide for New Zealand Spinach

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

Month New Zealand Spinach Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.3" 1.5" 2.8" 🚿 Regular watering
May 4.3" 1.4" 2.9" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 0.4" 3.9" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.8" 3.5" 🚿 Regular watering
Oct 4.3" 2" 2.3" 🚿 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.

New Zealand Spinach 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.

New Zealand Spinach needs ~1,000 GDD — county provides 3,312 GDD Excellent fit

New Zealand Spinach Planting Timeline — Benton County, WA

New Zealand Spinach Planting Calendar

Activity When Date Range
Start Indoors February 13 Feb 13 – Feb 27
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 10 Apr 10 – May 1
Harvest June 12 Jun 12 – Jul 10

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

207 days in Benton County

Growing Tips for New Zealand Spinach in Benton County

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

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

General growing tips

Soak seeds overnight before planting. Direct sow after last frost. Pinch growing tips regularly to encourage bushy growth and tender new leaves.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant New Zealand Spinach in Benton County, WA?

Benton County is in Zone 7b with an average last frost of April 3. Plan your New Zealand Spinach 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.