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When to Plant Kai Lan in Waushara 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.

Waushara County, Wisconsin is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 9, giving you a growing season of approximately 162 days.

At an elevation of 560 feet, Waushara County receives approximately 37.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Kai Lan to ensure they mature before fall.

Waushara County, WI (Zone 4b) Moderate season
162 days
Last Spring Frost April 30
162 growing days
First Fall Frost October 9

Waushara County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Mar 14 Transplant: Apr 25 🍅 Harvest: Jun 13 – Jul 11
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 19 Transplant: Apr 30 🍅 Harvest: Jun 18 – Jul 16
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Apr 6 Transplant: May 18 🍅 Harvest: Jul 6 – Aug 3

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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 44 gal / 100 sq ft
Kai Lan needs ~564 GDD — county provides 1,741 GDD Excellent fit

Kai Lan Planting Timeline โ€” Waushara County, WI

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Direct Sow April 23 Apr 23 โ€“ May 14
Fall Sowing July 17 Jul 17 โ€“ Jul 31
Harvest June 18 Jun 18 โ€“ Jul 16

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August โ€”
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 4b

Growing Season

162 days

Growing Tips for Waushara 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 Waushara County, WI?

Waushara County is in Zone 4b with an average last frost of April 30. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Waushara County, WI?

Waushara County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 9.

๐ŸŒฑ

Plan Your Garden with Confidence

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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 Waushara County, WI. Local conditions may vary. Last updated: April 2026.