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When to Plant Kai Lan in Lake County, CO

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.

Lake County, Colorado is in USDA Zone 4a. The average last spring frost is June 21 and the first fall frost is August 30, giving you a growing season of approximately 70 days.

At an elevation of 7,687 feet, Lake County receives approximately 21.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Kai Lan to ensure they mature before fall.

Lake County, CO (Zone 4a) Very short season
70 days
Last Spring Frost June 21
70 growing days
First Fall Frost August 30

Lake County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.2

Drainage

Well Drained

Monthly Watering Guide for Kai Lan

Kai Lan needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Kai Lan Needs Rainfall You Supplement Action
Jan โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.1" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr โ€” 2.1" 0" โ„๏ธ Dormant
May โ€” 2.7" 0" โ„๏ธ Dormant
Jun 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Jul 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Aug 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Sep โ€” 1.6" 0" โ„๏ธ Dormant
Oct โ€” 2.1" 0" โ„๏ธ Dormant
Nov โ€” 1.6" 0" โ„๏ธ Dormant
Dec โ€” 1.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Aug in Lake County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Kai Lan Planting Timeline โ€” Lake County, CO

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors May 10 May 10 โ€“ May 24
Transplant Outdoors June 21 Jun 21 โ€“ Jul 5
Direct Sow June 14 Jun 14 โ€“ Jul 5
Harvest August 9 Aug 9 โ€“ Sep 6
Fall Sowing June 7 Jun 7 โ€“ Jun 21

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

45โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

70 days in Lake County

Growing Tips for Lake 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kai Lan in Lake County, CO?

Lake County is in Zone 4a with an average last frost of June 21. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lake County, CO?

Lake County, Colorado is in USDA Hardiness Zone 4a. The average last spring frost is June 21 and first fall frost is August 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lake County gardeners in Zone 4a 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 Lake County, CO. Local conditions may vary. Last updated: April 2026.