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When to Plant Pac Choi in Barron County, WI

Barron County, Wisconsin Zone 4b May

May to-do list for Barron County, Wisconsin

We've pulled the most time-sensitive tasks for Barron County, Wisconsin this May and put them front and centre. Tackle them in order.

Avg. last frost May 17
Avg. first frost September 25
Soil temp (4") 53°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Plant out pac choi

    Frost risk is low now in Barron County, Wisconsin. If you've been covering beds overnight, you can stop.

  2. Seed pac choi outdoors

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

A few tasks this May that'll pay off in June
  • Starting indoors: pac choi
  • First harvests: pac choi

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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.

Barron County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 17 and the first fall frost is September 25, giving you a growing season of approximately 131 days.

At an elevation of 1,256 feet, Barron County receives approximately 40.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Pac Choi to ensure they mature before fall.

Barron County, WI (Zone 4b) Short season
131 days
Last Spring Frost May 17
131 growing days
First Fall Frost September 25

Barron County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Jun 25 – Jul 23
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Apr 5 Transplant: May 17 🍅 Harvest: Jun 28 – Jul 26
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Apr 20 Transplant: Jun 1 🍅 Harvest: Jul 13 – Aug 10

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 Barron County

How your county's soil matches Pac Choi's growing requirements.

Soil pH

Your soil pH (5.8–7.0) overlaps with Pac Choi's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Barron County is excellent for Pac Choi — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.9%) — Pac Choi will thrive.

How to Plant Pac Choi

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Pac Choi

3
successive plantings in your 131-day season

Sow every 4.6 weeks. Last sowing by Aug 01 to harvest before frost.

For a dedicated fall crop, sow by Jul 03.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.3″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 239 gal / 100 sq ft

Monthly Watering Guide for Pac Choi

Pac Choi 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 Pac Choi Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 0" ❄️ Dormant
May 6.5" 4.6" 1.9" 💧 Light watering
Jun 6.5" 5.6" 0.9" 💧 Light watering
Jul 6.5" 3.9" 2.6" 💧 Light watering
Aug 6.5" 4" 2.5" 💧 Light watering
Sep 6.5" 3.3" 3.2" 💧 Light watering
Oct 3" 0" ❄️ Dormant
Nov 3.2" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Barron County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Pac Choi 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" — every day above 50°F 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.

Pac Choi needs ~582 GDD — county provides 1,604 GDD Excellent fit

Pac Choi Planting Timeline — Barron County, WI

Pac Choi Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 10 May 10 – May 31
Harvest June 28 Jun 28 – Jul 26
Fall Sowing July 3 Jul 3 – Jul 17

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

40–55 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

131 days in Barron County

Growing Tips for Pac Choi in Barron County

Direct sow Pac Choi outdoors after May 17 in Barron County when soil has warmed and frost danger has passed.

Common pests for Pac Choi 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. 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pac Choi in Barron County, WI?

Barron County is in Zone 4b with an average last frost of May 17. Plan your Pac Choi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Barron County, WI?

Barron County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 17 and first fall frost is September 25.

🌱

Your Barron County Garden Planner — Free

A 24-page printable planner built for Barron County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Barron County, WI. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.