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When to Plant Bok Choy in Campbell County, WY

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.

Campbell County, Wyoming is in USDA Zone 4a. The average last spring frost is May 20 and the first fall frost is September 20, giving you a growing season of approximately 123 days.

At an elevation of 8,132 feet, Campbell County receives approximately 22.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Bok Choy to ensure they mature before fall.

Campbell County, WY (Zone 4a) Short season
123 days
Last Spring Frost May 20
123 growing days
First Fall Frost September 20

Campbell 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 (46 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Jun 25 – Jul 30
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Apr 8 Transplant: May 20 🍅 Harvest: Jul 1 – Aug 5
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Apr 26 Transplant: Jun 7 🍅 Harvest: Jul 19 – 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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 970 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Bok Choy needs ~612 GDD — county provides 1,506 GDD Excellent fit

Bok Choy Planting Timeline โ€” Campbell County, WY

Bok Choy Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 โ€“ Apr 22
Transplant Outdoors May 20 May 20 โ€“ Jun 3
Direct Sow May 13 May 13 โ€“ Jun 3
Fall Sowing June 28 Jun 28 โ€“ Jul 12
Harvest July 1 Jul 1 โ€“ Aug 5

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 4a

Growing Season

123 days

Growing Tips for Campbell County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Bok Choy in Campbell County, WY?

Campbell County is in Zone 4a with an average last frost of May 20. Plan your Bok Choy planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Campbell County, WY?

Campbell County, Wyoming is in USDA Hardiness Zone 4a. The average last spring frost is May 20 and first fall frost is September 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Campbell County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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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 Campbell County, WY. Local conditions may vary. Last updated: April 2026.