Blog

When to Plant Kai Lan in Montrose 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.

Montrose County, Colorado is in USDA Zone 6a. The average last spring frost is June 13 and the first fall frost is September 12, giving you a growing season of approximately 91 days.

At an elevation of 6,494 feet, Montrose County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Kai Lan during the growing season. With low rainfall, drip irrigation is essential for growing Kai Lan successfully. Mulch heavily to conserve soil moisture.

Montrose County, CO (Zone 6a) Very short season
91 days
Last Spring Frost June 13
91 growing days
First Fall Frost September 12

Montrose County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (39 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jul 2 – Jul 30
Recommended (50%) ✓ Fits season (14 days to spare)
Start indoors: May 9 Transplant: Jun 13 🍅 Harvest: Aug 1 – Aug 29
Safe Start (90%) ✓ Fits season (32 days to spare)
Start indoors: May 22 Transplant: Jun 26 🍅 Harvest: Aug 14 – Sep 11

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 Montrose County

How your county's soil matches Kai Lan's growing requirements.

Soil pH

Your soil pH (6.7โ€“7.9) overlaps with Kai Lan's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Montrose County is excellent for Kai Lan โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Kai Lan.

How to Plant Kai Lan

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Kai Lan

2
successive plantings in your 91-day season

Sow every 5.1 weeks. Last sowing by Jul 14 to harvest before frost.

For a dedicated fall crop, sow by Jul 04.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 147 gal / 100 sq ft
Drought risk

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

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€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.4" 0" โ„๏ธ Dormant
Apr โ€” 2.2" 0" โ„๏ธ Dormant
May โ€” 2.3" 0" โ„๏ธ Dormant
Jun 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Jul 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Aug 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Sep 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Oct โ€” 1.6" 0" โ„๏ธ Dormant
Nov โ€” 1.3" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

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

Kai Lan 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" โ€” every day above 50ยฐF 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.

Kai Lan needs ~801 GDD — county provides 1,387 GDD Excellent fit

Kai Lan Planting Timeline โ€” Montrose County, CO

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors May 9 May 9 โ€“ May 23
Transplant Outdoors June 13 Jun 13 โ€“ Jun 27
Direct Sow May 30 May 30 โ€“ Jun 20
Harvest August 1 Aug 1 โ€“ Aug 29
Fall Sowing July 4 Jul 4 โ€“ Jul 18

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 Direct Sow
June Transplant Outdoors Direct Sow
July Fall Sowing
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

45โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

91 days in Montrose County

Growing Tips for Kai Lan in Montrose County

Direct sow Kai Lan outdoors after June 13 in Montrose County when soil has warmed and frost danger has passed.

Common pests for Kai Lan in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Montrose County receives only 18" of rain annually. Kai Lan needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Montrose County, CO?

Montrose County is in Zone 6a with an average last frost of June 13. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Montrose County, CO?

Montrose County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is June 13 and first fall frost is September 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Montrose County gardeners in Zone 6a 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 Montrose County, CO. Local conditions may vary. Last updated: April 2026.