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When to Plant Bok Choy in Okanogan County, WA

Bok choy is a Chinese cabbage variety with crisp white stalks and dark green leaves. It is a fast-growing cool-season crop ideal for stir-fries and soups.

Okanogan County, Washington is in USDA Zone 5b. The average last spring frost is May 13 and the first fall frost is September 26, giving you a growing season of approximately 136 days.

At an elevation of 3,788 feet, Okanogan County receives approximately 21.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Bok Choy to ensure they mature before fall.

Okanogan County, WA (Zone 5b) Short season
136 days
Last Spring Frost May 13
136 growing days
First Fall Frost September 26

Okanogan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 19 – Jul 24
Recommended (50%) ✓ Fits season (59 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jun 24 – Jul 29
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Jul 18 – Aug 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 Okanogan County

How your county's soil matches Bok Choy's growing requirements.

Soil pH

Your soil pH (5.4โ€“6.5) is more acidic than Bok Choy prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Okanogan County is excellent for Bok Choy โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

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

Organic Matter

Organic matter is excellent (5.6%) โ€” Bok Choy will thrive.

How to Plant Bok Choy

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 Bok Choy

4
successive plantings in your 136-day season

Sow every 4.6 weeks. Last sowing by Jul 28 to harvest before frost.

For a dedicated fall crop, sow by Jul 18.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 305 gal / 100 sq ft

Monthly Watering Guide for Bok Choy

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

Month Bok Choy Needs Rainfall You Supplement Action
Jan โ€” 2.9" 0" โ„๏ธ Dormant
Feb โ€” 2.4" 0" โ„๏ธ Dormant
Mar โ€” 2.3" 0" โ„๏ธ Dormant
Apr โ€” 1.4" 0" โ„๏ธ Dormant
May 3" 1.3" 1.7" ๐Ÿšฟ Regular watering
Jun 3" 0.7" 2.3" ๐Ÿšฟ Regular watering
Jul 3" 0.3" 2.7" ๐Ÿšฟ Regular watering
Aug 3" 0.4" 2.6" ๐Ÿšฟ Regular watering
Sep 3" 0.7" 2.3" ๐Ÿšฟ Regular watering
Oct โ€” 1.7" 0" โ„๏ธ Dormant
Nov โ€” 3.6" 0" โ„๏ธ Dormant
Dec โ€” 3.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Okanogan County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Bok Choy 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.

Bok Choy needs ~612 GDD — county provides 1,666 GDD Excellent fit

Bok Choy Planting Timeline โ€” Okanogan County, WA

Bok Choy Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 โ€“ Apr 22
Transplant Outdoors May 13 May 13 โ€“ May 27
Direct Sow April 29 Apr 29 โ€“ May 20
Harvest June 24 Jun 24 โ€“ Jul 29
Fall Sowing July 18 Jul 18 โ€“ Aug 1

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

136 days in Okanogan County

Growing Tips for Bok Choy in Okanogan County

Direct sow Bok Choy outdoors after May 13 in Okanogan County when soil has warmed and frost danger has passed.

Common pests for Bok Choy 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 spring or fall for best results. Keep soil consistently moist. Harvest whole heads or cut outer leaves for a cut-and-come-again approach.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Bok Choy in Okanogan County, WA?

Okanogan County is in Zone 5b with an average last frost of May 13. Plan your Bok Choy planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Okanogan County, WA?

Okanogan County, Washington is in USDA Hardiness Zone 5b. The average last spring frost is May 13 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Okanogan County gardeners in Zone 5b 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 Okanogan County, WA. Local conditions may vary. Last updated: April 2026.