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When to Plant Mustard Greens in Northwest Arctic Borough, AK

Northwest Arctic Borough, Alaska Zone 2a May

This month in Northwest Arctic Borough, Alaska

Your garden in Northwest Arctic Borough, Alaska is working on a schedule, even when you're not. Here's where you should be this May.

Soil temp (4") 44°F
Watering High
Pest pressure Low
Daylight 19 hrs

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Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

Northwest Arctic Borough, Alaska is in USDA Zone 2a. The average last spring frost is May 18 and the first fall frost is August 6, giving you a growing season of approximately 80 days.

At an elevation of 2,144 feet, Northwest Arctic Borough receives approximately 42.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 56°F, so choose short-season varieties of Mustard Greens to ensure they mature before fall.

Northwest Arctic Borough, AK (Zone 2a) Very short season
80 days
Last Spring Frost May 18
80 growing days
First Fall Frost August 6

Northwest Arctic Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: May 20 – Jul 22
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: May 20 – Jul 22
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: May 20 – Jul 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 Northwest Arctic Borough

How your county's soil matches Mustard Greens's growing requirements.

Soil pH

Your soil pH (5.0–6.7) is more acidic than Mustard Greens prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Northwest Arctic Borough is excellent for Mustard Greens — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Mustard Greens.

Organic Matter

Organic matter is excellent (6.7%) — Mustard Greens will thrive.

How to Plant Mustard Greens

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
2.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Mustard Greens

Mustard Greens needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Mustard Greens Needs Rainfall You Supplement Action
Jan 2.1" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 3" 2" 1" 💧 Light watering
Jun 3" 2.9" 0.1" 💧 Light watering
Jul 3" 6" 0" ✅ Rainfall sufficient
Aug 3" 6.1" 0" ✅ Rainfall sufficient
Sep 8.6" 0" ❄️ Dormant
Oct 4.7" 0" ❄️ Dormant
Nov 3.1" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Aug in Northwest Arctic Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Mustard Greens 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.

Mustard Greens needs ~0 GDD — county provides 0 GDD May not mature

Mustard Greens Planting Timeline — Northwest Arctic Borough, AK

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 – Apr 20
Transplant Outdoors May 18 May 18 – Jun 1
Direct Sow May 11 May 11 – Jun 1
Harvest June 22 Jun 22 – Aug 24
Fall Sowing May 14 May 14 – May 28

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 2a

📆 Growing Season

80 days in Northwest Arctic Borough

Growing Tips for Mustard Greens in Northwest Arctic Borough

Common pests for Mustard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mustard Greens in Northwest Arctic Borough, AK?

Northwest Arctic Borough is in Zone 2a with an average last frost of May 18. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Northwest Arctic Borough, AK?

Northwest Arctic Borough, Alaska is in USDA Hardiness Zone 2a. The average last spring frost is May 18 and first fall frost is August 6.

🌱

Your Northwest Arctic Borough Garden Planner — Free

A 24-page printable planner built for Northwest Arctic Borough (Zone 2a). 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 Northwest Arctic 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.