Blog

When to Plant New Zealand Spinach in Mackinac County, MI

Mackinac County, Michigan Zone 5a May

Your May planting checklist for Mackinac County, Michigan

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 May 12
Avg. first frost October 10
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.8 hrs
  1. Set out new zealand spinach seedlings

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Outdoor sowing time: new zealand spinach

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

Instant PDF download. No spam, unsubscribe any time.

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.

Mackinac County, Michigan is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 10, giving you a growing season of approximately 151 days.

At an elevation of 1,335 feet, Mackinac County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of New Zealand Spinach to ensure they mature before fall.

Mackinac County, MI (Zone 5a) Moderate season
151 days
Last Spring Frost May 12
151 growing days
First Fall Frost October 10

Mackinac County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Mar 10 Transplant: May 19 🍅 Harvest: Jul 14 – Aug 11
Recommended (50%) ✓ Fits season (53 days to spare)
Start indoors: Mar 17 Transplant: May 26 🍅 Harvest: Jul 21 – Aug 18
Safe Start (90%) ✓ Fits season (54 days to spare)
Start indoors: Apr 1 Transplant: Jun 10 🍅 Harvest: Aug 5 – Sep 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 Mackinac County

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

Soil pH

Your soil pH (6.2–6.9) is within New Zealand Spinach's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — 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

3
successive plantings in your 151-day season

Sow every 6.3 weeks. Last sowing by Aug 01 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 32 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 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Mackinac 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 ~625 GDD — county provides 1,510 GDD Excellent fit

New Zealand Spinach Planting Timeline — Mackinac County, MI

New Zealand Spinach Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 19 May 19 – Jun 9
Harvest July 21 Jul 21 – Aug 18

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors 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: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

151 days in Mackinac County

Growing Tips for New Zealand Spinach in Mackinac County

Direct sow New Zealand Spinach outdoors after May 12 in Mackinac County when soil has warmed and frost danger has passed.

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 Mackinac County, MI?

Mackinac County is in Zone 5a with an average last frost of May 12. Plan your New Zealand Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mackinac County, MI?

Mackinac County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 10.

🌱

Your Mackinac County Garden Planner — Free

A 24-page printable planner built for Mackinac County (Zone 5a). 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 Mackinac County, MI. 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.