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When to Plant New Zealand Spinach in Petersburg Borough, AK

Petersburg Borough, Alaska Zone 7b May

Petersburg Borough, Alaska gardeners: here's your May plan

Here's what deserves your attention in Petersburg Borough, Alaska this month. Everything below is tailored to Zone 7b and timed around your local frost dates.

Avg. last frost April 23
Avg. first frost October 20
Soil temp (4") 63°F
Watering Critical
Pest pressure Moderate
Daylight 16.2 hrs
  1. Harden off and plant new zealand spinach

    Frost risk is low now in Petersburg Borough, Alaska. If you've been covering beds overnight, you can stop.

Coming up in June — start thinking about
  • Starting indoors: 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.

Petersburg Borough, Alaska is in USDA Zone 7b. The average last spring frost is April 23 and the first fall frost is October 20, giving you a growing season of approximately 180 days.

At an elevation of 974 feet, Petersburg Borough receives approximately 17.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 57°F, so choose short-season varieties of New Zealand Spinach to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing New Zealand Spinach successfully. Mulch heavily to conserve soil moisture.

Petersburg Borough, AK (Zone 7b) Moderate season
180 days
Last Spring Frost April 23
180 growing days
First Fall Frost October 20
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Petersburg Borough Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Start indoors: Feb 26 Transplant: Apr 30 🍅 Harvest: Jun 25 – Jul 23
Recommended (50%) ✓ Fits season (82 days to spare)
Start indoors: Mar 5 Transplant: May 7 🍅 Harvest: Jul 2 – Jul 30
Safe Start (90%) ✓ Fits season (83 days to spare)
Start indoors: Mar 24 Transplant: May 26 🍅 Harvest: Jul 21 – Aug 18

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 Petersburg Borough

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

Soil pH

Your soil pH (4.9–6.3) 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 Petersburg Borough is excellent for New Zealand Spinach — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for New Zealand Spinach.

Organic Matter

Organic matter is excellent (6.8%) — 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 180-day season

Sow every 6.3 weeks. Last sowing by Aug 11 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 471 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 0.9" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 0.7" 0" ❄️ Dormant
Apr 4.3" 0.5" 3.8" 🚿 Regular watering
May 4.3" 0.7" 3.6" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Petersburg Borough). 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 ~0 GDD — county provides 0 GDD May not mature

New Zealand Spinach Planting Timeline — Petersburg Borough, AK

New Zealand Spinach Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Harvest July 2 Jul 2 – Jul 30

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 7b

📆 Growing Season

180 days in Petersburg Borough

Growing Tips for New Zealand Spinach in Petersburg Borough

Direct sow New Zealand Spinach outdoors after April 23 in Petersburg Borough when soil has warmed and frost danger has passed.

Petersburg Borough receives only 17" 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 Petersburg Borough, AK?

Petersburg Borough is in Zone 7b with an average last frost of April 23. Plan your New Zealand Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Petersburg Borough, AK?

Petersburg Borough, Alaska is in USDA Hardiness Zone 7b. The average last spring frost is April 23 and first fall frost is October 20.

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Your Petersburg Borough Garden Planner — Free

A 24-page printable planner built for Petersburg Borough (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 Petersburg Borough, AK. 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.