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When to Plant New Zealand Spinach in Boise County, ID

Boise County, Idaho Zone 7a May

May in the garden — Boise County, Idaho

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Boise County, Idaho.

Avg. last frost May 18
Avg. first frost September 27
Soil temp (4") 34°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Plant new zealand spinach from seed, right in the garden

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

To set up a strong June, finish these tasks
  • Transplants going out: 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.

Boise County, Idaho is in USDA Zone 7a. The average last spring frost is May 18 and the first fall frost is September 27, giving you a growing season of approximately 132 days.

At an elevation of 8,023 feet, Boise County receives approximately 24.3 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for New Zealand Spinach during the growing season.

Boise County, ID (Zone 7a) Short season
132 days
Last Spring Frost May 18
132 growing days
First Fall Frost September 27

Boise County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Mar 17 Transplant: May 19 🍅 Harvest: Jul 14 – Aug 11
Recommended (50%) ✓ Fits season (34 days to spare)
Start indoors: Mar 30 Transplant: Jun 1 🍅 Harvest: Jul 27 – Aug 24
Safe Start (90%) ✓ Fits season (33 days to spare)
Start indoors: Apr 28 Transplant: Jun 30 🍅 Harvest: Aug 25 – Sep 22

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 Boise County

How your county's soil matches New Zealand Spinach's growing requirements.

Soil pH

Your soil pH (6.7–7.7) overlaps with New Zealand Spinach's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help New Zealand Spinach.

How to Plant New Zealand Spinach

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

Succession Planting New Zealand Spinach

2
successive plantings in your 132-day season

Sow every 6.3 weeks. Last sowing by Jul 19 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 320 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.8" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 2.4" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Boise 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 ~906 GDD — county provides 1,914 GDD Excellent fit

New Zealand Spinach Planting Timeline — Boise County, ID

New Zealand Spinach Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors June 1 Jun 1 – Jun 15
Direct Sow May 25 May 25 – Jun 15
Harvest July 27 Jul 27 – Aug 24

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

132 days in Boise County

Growing Tips for New Zealand Spinach in Boise County

Direct sow New Zealand Spinach outdoors after May 18 in Boise County when soil has warmed and frost danger has passed.

Boise County receives only 24" 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 Boise County, ID?

Boise County is in Zone 7a with an average last frost of May 18. Plan your New Zealand Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Boise County, ID?

Boise County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 18 and first fall frost is September 27.

🌱

Your Boise County Garden Planner — Free

A 24-page printable planner built for Boise County (Zone 7a). 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 Boise County, ID. 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.