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When to Plant Kai Lan in Outagamie 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.

Outagamie County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 8 and the first fall frost is October 5, giving you a growing season of approximately 150 days.

At an elevation of 1,052 feet, Outagamie County receives approximately 36.7 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.

Outagamie County, WI (Zone 4b) Moderate season
150 days
Last Spring Frost May 8
150 growing days
First Fall Frost October 5

Outagamie County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🍅 Harvest: Jun 17 – Jul 15
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Mar 27 Transplant: May 8 🍅 Harvest: Jun 26 – Jul 24
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Apr 9 Transplant: May 21 🍅 Harvest: Jul 9 – Aug 6

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
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Kai Lan needs ~643 GDD — county provides 1,837 GDD Excellent fit

Kai Lan Planting Timeline โ€” Outagamie County, WI

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 โ€“ Apr 10
Transplant Outdoors May 8 May 8 โ€“ May 22
Direct Sow May 1 May 1 โ€“ May 22
Fall Sowing July 13 Jul 13 โ€“ Jul 27
Harvest June 26 Jun 26 โ€“ Jul 24

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
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

150 days

Growing Tips for Outagamie 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 Outagamie County, WI?

Outagamie County is in Zone 4b with an average last frost of May 8. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Outagamie County, WI?

Outagamie County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 8 and first fall frost is October 5.

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