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When to Plant Chinese Cabbage in Snohomish County, WA

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

Snohomish County, Washington is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 2, giving you a growing season of approximately 222 days.

At an elevation of 230 feet, Snohomish County receives approximately 50.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Chinese Cabbage during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Chinese Cabbage root diseases.

Snohomish County, WA (Zone 8a) Long season
222 days
Last Spring Frost March 25
222 growing days
First Fall Frost November 2

Snohomish County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (139 days to spare)
Start indoors: Feb 12 Transplant: Mar 19 🍅 Harvest: May 14 – Jun 11
Recommended (50%) ✓ Fits season (138 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 20 – Jun 17
Safe Start (90%) ✓ Fits season (137 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jun 13 – Jul 11

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 Snohomish County

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

Soil pH

Your soil pH (5.7โ€“6.8) overlaps with Chinese Cabbage's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The silt loam soil in Snohomish County is excellent for Chinese Cabbage โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.4%) โ€” Chinese Cabbage will thrive.

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

5
successive plantings in your 222-day season

Sow every 5.7 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Aug 24.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,072 gal / 100 sq ft

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 โ€” 7.7" 0" โ„๏ธ Dormant
Feb โ€” 5.6" 0" โ„๏ธ Dormant
Mar 6.5" 5" 1.5" ๐Ÿ’ง Light watering
Apr 6.5" 3.6" 2.9" ๐Ÿ’ง Light watering
May 6.5" 2.6" 3.9" ๐Ÿšฟ Regular watering
Jun 6.5" 1.6" 4.9" ๐Ÿšฟ Regular watering
Jul 6.5" 0.7" 5.8" ๐Ÿšฟ Regular watering
Aug 6.5" 1" 5.5" ๐Ÿšฟ Regular watering
Sep 6.5" 2" 4.5" ๐Ÿšฟ Regular watering
Oct 6.5" 4.2" 2.3" ๐Ÿ’ง Light watering
Nov 6.5" 8" 0" โœ… Rainfall sufficient
Dec โ€” 8.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Snohomish County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,050 GDD — county provides 3,885 GDD Excellent fit

Chinese Cabbage Planting Timeline โ€” Snohomish County, WA

Chinese Cabbage Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 โ€“ Mar 4
Transplant Outdoors March 25 Mar 25 โ€“ Apr 8
Direct Sow March 11 Mar 11 โ€“ Apr 1
Harvest May 20 May 20 โ€“ Jun 17
Fall Sowing August 24 Aug 24 โ€“ Sep 7

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

222 days in Snohomish County

Growing Tips for Chinese Cabbage in Snohomish County

Direct sow Chinese Cabbage outdoors after March 25 in Snohomish 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.

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 Snohomish County, WA?

Snohomish County is in Zone 8a with an average last frost of March 25. Plan your Chinese Cabbage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Snohomish County, WA?

Snohomish County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Snohomish County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Snohomish County, WA. Local conditions may vary. Last updated: April 2026.