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When to Plant Chinese Cabbage in Phillips County, MT

Phillips County, Montana Zone 3b May

Top priorities for Phillips County, Montana gardeners in May

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 18
Avg. first frost September 21
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Harden off and plant chinese cabbage

    Frost risk is low now in Phillips County, Montana. If you've been covering beds overnight, you can stop.

  2. Put chinese cabbage seeds straight in the ground

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

Before June arrives, get these ready
  • Starting indoors: chinese cabbage
  • Fall sowing: chinese cabbage

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Chinese cabbage (Napa cabbage) forms elongated, barrel-shaped heads with tender, mild-flavored leaves. It is a staple in Asian cooking, particularly for kimchi.

Phillips County, Montana is in USDA Zone 3b. The average last spring frost is May 18 and the first fall frost is September 21, giving you a growing season of approximately 126 days.

At an elevation of 6,886 feet, Phillips County receives approximately 19 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Chinese Cabbage to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Chinese Cabbage successfully. Mulch heavily to conserve soil moisture.

Phillips County, MT (Zone 3b) Short season
126 days
Last Spring Frost May 18
126 growing days
First Fall Frost September 21

Phillips County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (40 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 7 – Aug 4
Recommended (50%) ✓ Fits season (42 days to spare)
Start indoors: Apr 6 Transplant: May 18 🍅 Harvest: Jul 13 – Aug 10
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Apr 19 Transplant: May 31 🍅 Harvest: Jul 26 – Aug 23

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 Phillips County

How your county's soil matches Chinese Cabbage's growing requirements.

Soil pH

Your soil pH (6.7–7.6) overlaps with Chinese Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Phillips County is excellent for Chinese Cabbage — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Chinese Cabbage.

How to Plant Chinese Cabbage

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Succession Planting Chinese Cabbage

2
successive plantings in your 126-day season

Sow every 5.7 weeks. Last sowing by Jul 13 to harvest before frost.

For a dedicated fall crop, sow by Jun 29.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,166 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Chinese Cabbage

Chinese Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Chinese Cabbage Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.9" 0" ❄️ Dormant
May 6.5" 2.4" 4.1" 🚿 Regular watering
Jun 6.5" 1.4" 5.1" 🚿 Regular watering
Jul 6.5" 1.6" 4.9" 🚿 Regular watering
Aug 6.5" 2" 4.5" 🚿 Regular watering
Sep 6.5" 1.4" 5.1" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

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

Chinese Cabbage 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.

Chinese Cabbage needs ~600 GDD — county provides 1,260 GDD Excellent fit

Chinese Cabbage Planting Timeline — Phillips County, MT

Chinese Cabbage 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 July 13 Jul 13 – Aug 10
Fall Sowing June 29 Jun 29 – Jul 13

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 3b

📆 Growing Season

126 days in Phillips County

Growing Tips for Chinese Cabbage in Phillips County

Direct sow Chinese Cabbage outdoors after May 18 in Phillips County when soil has warmed and frost danger has passed.

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

Phillips County receives only 19" of rain annually. Chinese Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Best grown as a fall crop to avoid bolting. Start seeds indoors or direct sow in late summer. Keep soil consistently moist and provide shade in warm weather.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chinese Cabbage in Phillips County, MT?

Phillips County is in Zone 3b with an average last frost of May 18. Plan your Chinese Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Phillips County, MT?

Phillips County, Montana is in USDA Hardiness Zone 3b. The average last spring frost is May 18 and first fall frost is September 21.

🌱

Your Phillips County Garden Planner — Free

A 24-page printable planner built for Phillips County (Zone 3b). 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 Phillips County, MT. 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.