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When to Plant Pac Choi in Boone County, IL

Pac choi (baby bok choy) is a compact variety of Chinese cabbage with tender leaves and crisp stems. It grows quickly and is ideal for containers and small spaces.

Boone County, Illinois is in USDA Zone 5a. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.

At an elevation of 512 feet, Boone County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Pac Choi to ensure they mature before fall.

Boone County, IL (Zone 5a) Moderate season
176 days
Last Spring Frost April 23
176 growing days
First Fall Frost October 16

Boone County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (107 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 29 – Jun 26
Recommended (50%) ✓ Fits season (106 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 4 – Jul 2
Safe Start (90%) ✓ Fits season (103 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Jun 21 – Jul 19

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
1.0″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 1,876 gal / 100 sq ft
Drought risk

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

Pac Choi needs ~582 GDD — county provides 2,156 GDD Excellent fit

Pac Choi Planting Timeline โ€” Boone County, IL

Pac Choi Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Direct Sow April 9 Apr 9 โ€“ Apr 30
Fall Sowing August 7 Aug 7 โ€“ Aug 21
Harvest June 4 Jun 4 โ€“ Jul 2

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors
June Harvest
July Harvest
August Fall Sowing
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€“55 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5a

Growing Season

176 days

Growing Tips for Boone County

Direct sow in spring or fall. Grows best in cool weather. Space 6 inches apart for baby pac choi. Harvest whole plants or cut outer leaves as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Pac Choi in Boone County, IL?

Boone County is in Zone 5a with an average last frost of April 23. Plan your Pac Choi planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Boone County, IL?

Boone County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 23 and first fall frost is October 16.

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Plan Your Garden with Confidence

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