Blog

When to Plant Kai Lan in Denali Borough, AK

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.

Denali Borough, Alaska is in USDA Zone 2b. The average last spring frost is June 2 and the first fall frost is August 25, giving you a growing season of approximately 84 days.

At an elevation of 2,930 feet, Denali Borough receives approximately 15.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 70ยฐF, so choose short-season varieties of Kai Lan to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Kai Lan successfully. Mulch heavily to conserve soil moisture.

Denali Borough, AK (Zone 2b) Very short season
84 days
Last Spring Frost June 2
84 growing days
First Fall Frost August 25

Denali Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Start indoors: Apr 16 Transplant: May 28 🍅 Harvest: Jul 16 – Aug 13
Recommended (50%) ✓ Fits season (7 days to spare)
Start indoors: Apr 21 Transplant: Jun 2 🍅 Harvest: Jul 21 – Aug 18
Safe Start (90%) ✗ May not fit
Start indoors: May 10 Transplant: Jun 21 🍅 Harvest: Aug 9 – Sep 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.

Soil Compatibility in Denali Borough

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

Soil pH

Your soil pH (5.2โ€“6.6) is more acidic than Kai Lan prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Kai Lan.

Organic Matter

Organic matter is excellent (6.0%) โ€” Kai Lan will thrive.

How to Plant Kai Lan

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Kai Lan

2
successive plantings in your 84-day season

Sow every 5.1 weeks. Last sowing by Jun 26 to harvest before frost.

For a dedicated fall crop, sow by Jun 02.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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€” 0.8" 0" โ„๏ธ Dormant
Feb โ€” 0.6" 0" โ„๏ธ Dormant
Mar โ€” 0.6" 0" โ„๏ธ Dormant
Apr โ€” 0.5" 0" โ„๏ธ Dormant
May โ€” 0.7" 0" โ„๏ธ Dormant
Jun 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Jul 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Aug 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Sep โ€” 2.8" 0" โ„๏ธ Dormant
Oct โ€” 2" 0" โ„๏ธ Dormant
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Aug in Denali Borough). 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 ~131 GDD — county provides 210 GDD Excellent fit

Kai Lan Planting Timeline โ€” Denali Borough, AK

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors April 21 Apr 21 โ€“ May 5
Transplant Outdoors June 2 Jun 2 โ€“ Jun 16
Direct Sow May 26 May 26 โ€“ Jun 16
Harvest July 21 Jul 21 โ€“ Aug 18
Fall Sowing June 2 Jun 2 โ€“ Jun 16

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 Start Indoors Direct Sow
June Transplant Outdoors Direct Sow Fall Sowing
July Harvest
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 Natural rainfall sufficient

๐Ÿ“… Days to Maturity

45โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 2b

๐Ÿ“† Growing Season

84 days in Denali Borough

Growing Tips for Kai Lan in Denali Borough

Direct sow Kai Lan outdoors after June 02 in Denali Borough 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.

Denali Borough receives only 16" 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 Denali Borough, AK?

Denali Borough is in Zone 2b with an average last frost of June 2. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Denali Borough, AK?

Denali Borough, Alaska is in USDA Hardiness Zone 2b. The average last spring frost is June 2 and first fall frost is August 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Denali Borough gardeners in Zone 2b 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 Denali Borough, AK. Local conditions may vary. Last updated: April 2026.