Blog

When to Plant Pac Choi in Marion County, IA

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.

Marion County, Iowa is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 971 feet, Marion County receives approximately 33.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Pac Choi to ensure they mature before fall.

Marion County, IA (Zone 5a) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Marion County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (93 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 3 – Jul 1
Recommended (50%) ✓ Fits season (89 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 12 – Jul 10
Safe Start (90%) ✓ Fits season (89 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: Jun 26 – Jul 24

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
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 882 gal / 100 sq ft
Pac Choi needs ~618 GDD — county provides 2,067 GDD Excellent fit

Pac Choi Planting Timeline โ€” Marion County, IA

Pac Choi Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 โ€“ Apr 10
Transplant Outdoors May 1 May 1 โ€“ May 15
Direct Sow April 17 Apr 17 โ€“ May 8
Fall Sowing July 29 Jul 29 โ€“ Aug 12
Harvest June 12 Jun 12 โ€“ Jul 10

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 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

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

159 days

Growing Tips for Marion 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 Marion County, IA?

Marion County is in Zone 5a with an average last frost of May 1. Plan your Pac Choi planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marion County, IA?

Marion County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

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