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When to Plant Kai Lan in Shelby County, AL

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.

Shelby County, Alabama is in USDA Zone 7b. The average last spring frost is March 26 and the first fall frost is November 5, giving you a growing season of approximately 224 days.

At an elevation of 324 feet, Shelby County receives approximately 48.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90ยฐF, providing good warmth for Kai Lan during the growing season. Clay soil retains moisture well for Kai Lan, but amend with compost to improve drainage and prevent root rot.

Shelby County, AL (Zone 7b) Long season
224 days
Last Spring Frost March 26
224 growing days
First Fall Frost November 5

Shelby County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (149 days to spare)
Start indoors: Feb 12 Transplant: Mar 19 🍅 Harvest: May 7 – Jun 4
Recommended (50%) ✓ Fits season (147 days to spare)
Start indoors: Feb 19 Transplant: Mar 26 🍅 Harvest: May 14 – Jun 11
Safe Start (90%) ✓ Fits season (148 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: May 31 – Jun 28

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 Shelby County

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

Soil pH

Your soil pH (5.6โ€“6.5) overlaps with Kai Lan's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). 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

5
successive plantings in your 224-day season

Sow every 5.1 weeks. Last sowing by Sep 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 27.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 203 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€” 4.5" 0" โ„๏ธ Dormant
Feb โ€” 4.5" 0" โ„๏ธ Dormant
Mar 4.3" 4.4" 0" โœ… Rainfall sufficient
Apr 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
May 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jun 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Jul 4.3" 4.5" 0" โœ… Rainfall sufficient
Aug 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Sep 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Oct 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Nov 4.3" 4.4" 0" โœ… Rainfall sufficient
Dec โ€” 3.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Shelby 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 ~919 GDD — county provides 3,920 GDD Excellent fit

Kai Lan Planting Timeline โ€” Shelby County, AL

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 โ€“ Mar 5
Transplant Outdoors March 26 Mar 26 โ€“ Apr 9
Direct Sow March 12 Mar 12 โ€“ Apr 2
Harvest May 14 May 14 โ€“ Jun 11
Fall Sowing August 27 Aug 27 โ€“ Sep 10

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July โ€”
August Fall Sowing
September Fall Sowing
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 7b

๐Ÿ“† Growing Season

224 days in Shelby County

Growing Tips for Kai Lan in Shelby County

Direct sow Kai Lan outdoors after March 26 in Shelby County when soil has warmed and frost danger has passed.

With Shelby County's clay soil (33% clay), work in 3-4 inches of compost before planting Kai Lan. Avoid tilling when soil is wet to prevent compaction.

Your generous 224.0-day season in Shelby County allows multiple plantings of Kai Lan. Sow every 22.0 days for continuous harvest.

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.

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 Shelby County, AL?

Shelby County is in Zone 7b with an average last frost of March 26. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Shelby County, AL?

Shelby County, Alabama is in USDA Hardiness Zone 7b. The average last spring frost is March 26 and first fall frost is November 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Shelby County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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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 Shelby County, AL. Local conditions may vary. Last updated: April 2026.