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When to Plant Kai Lan in Barron County, WI

Kai lan (Chinese broccoli) is a brassica grown for its thick, glossy stems and small flower buds. It has a slightly bitter, broccoli-like flavor essential in Cantonese cooking.

Barron County, Wisconsin is in USDA Zone 4a. 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 83ยฐF, so choose short-season varieties of Kai Lan to ensure they mature before fall.

Barron County, WI (Zone 4a) 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 (46 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Jul 2 – Jul 30
Recommended (50%) ✓ Fits season (54 days to spare)
Start indoors: Apr 5 Transplant: May 17 🍅 Harvest: Jul 5 – Aug 2
Safe Start (90%) ✓ Fits season (53 days to spare)
Start indoors: Apr 20 Transplant: Jun 1 🍅 Harvest: Jul 20 – Aug 17

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
1.0″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Kai Lan needs ~643 GDD — county provides 1,604 GDD Excellent fit

Kai Lan Planting Timeline โ€” Barron County, WI

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 โ€“ Apr 19
Transplant Outdoors May 17 May 17 โ€“ May 31
Direct Sow May 10 May 10 โ€“ May 31
Fall Sowing July 3 Jul 3 โ€“ Jul 17
Harvest July 5 Jul 5 โ€“ Aug 2

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

45โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 4a

Growing Season

131 days

Growing Tips for Barron County

Direct sow in spring or fall. Harvest when flower buds first appear but before they open. Cut stems at the base to encourage side shoots. Prefers cool weather.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Kai Lan in Barron County, WI?

Barron County is in Zone 4a with an average last frost of May 17. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Barron County, WI?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Barron 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 Barron County, WI. Local conditions may vary. Last updated: April 2026.