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When to Plant Chinese Cabbage in Grand County, CO

Grand County, Colorado Zone 5a May

What to do in May

Each item below is timed to Grand County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 28
Avg. first frost September 19
Soil temp (4") 42°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
  1. Move chinese cabbage from tray to bed

    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: chinese cabbage

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

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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.

Grand County, Colorado is in USDA Zone 5a. The average last spring frost is May 28 and the first fall frost is September 19, giving you a growing season of approximately 114 days.

At an elevation of 5,397 feet, Grand County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Chinese Cabbage to ensure they mature before fall.

Grand County, CO (Zone 5a) Short season
114 days
Last Spring Frost May 28
114 growing days
First Fall Frost September 19
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Grand County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jul 8 – Aug 5
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Apr 23 Transplant: May 28 🍅 Harvest: Jul 23 – Aug 20
Safe Start (90%) ✓ Fits season (33 days to spare)
Start indoors: May 14 Transplant: Jun 18 🍅 Harvest: Aug 13 – Sep 10

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 Grand County

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

Soil pH

Your soil pH (6.7–8.3) overlaps with Chinese Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Chinese Cabbage is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Chinese Cabbage.

How to Plant Chinese Cabbage

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Chinese Cabbage

2
successive plantings in your 114-day season

Sow every 5.7 weeks. Last sowing by Jul 11 to harvest before frost.

For a dedicated fall crop, sow by Jul 11.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
1.4″/week
Watering frequency 2-3 times/week
Season total 1,378 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 6.5" 3" 3.5" 🚿 Regular watering
Jun 6.5" 1.5" 5" 🚿 Regular watering
Jul 6.5" 2" 4.5" 🚿 Regular watering
Aug 6.5" 2.3" 4.2" 🚿 Regular watering
Sep 6.5" 1.6" 4.9" 🚿 Regular watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Grand 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 ~690 GDD — county provides 1,311 GDD Excellent fit

Chinese Cabbage Planting Timeline — Grand County, CO

Chinese Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 23 Apr 23 – May 7
Transplant Outdoors May 28 May 28 – Jun 11
Direct Sow May 14 May 14 – Jun 4
Harvest July 23 Jul 23 – Aug 20
Fall Sowing July 11 Jul 11 – Jul 25

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Fall Sowing Harvest
August Harvest
September
October
November
December
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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 5a

📆 Growing Season

114 days in Grand County

Growing Tips for Chinese Cabbage in Grand County

Direct sow Chinese Cabbage outdoors after May 28 in Grand 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.

Grand County receives only 22" 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 Grand County, CO?

Grand County is in Zone 5a with an average last frost of May 28. Plan your Chinese Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grand County, CO?

Grand County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 28 and first fall frost is September 19.

🌱

Your Grand County Garden Planner — Free

A 24-page printable planner built for Grand 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.

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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 Grand County, CO. 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.