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When to Plant Kai Lan in Madison County, TN

Madison County, Tennessee Zone 7b May

What to do in May

Each item below is timed to Madison County, Tennessee's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 2
Avg. first frost October 28
Soil temp (4") 66°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Begin indoor sowing: kai lan

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Basket week: kai lan

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Coming up in June — start thinking about
  • First harvests: kai lan

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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.

Madison County, Tennessee is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is October 28, giving you a growing season of approximately 209 days.

At an elevation of 1,852 feet, Madison County receives approximately 46.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Kai Lan during the growing season.

Madison County, TN (Zone 7b) Long season
209 days
Last Spring Frost April 2
209 growing days
First Fall Frost October 28
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Madison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (134 days to spare)
Start indoors: Feb 19 Transplant: Mar 26 🍅 Harvest: May 14 – Jun 11
Recommended (50%) ✓ Fits season (132 days to spare)
Start indoors: Feb 26 Transplant: Apr 2 🍅 Harvest: May 21 – Jun 18
Safe Start (90%) ✓ Fits season (132 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jun 6 – Jul 4

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 Madison County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Kai Lan's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Madison County is excellent for Kai Lan — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). 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 209-day season

Sow every 5.1 weeks. Last sowing by Aug 29 to harvest before frost.

For a dedicated fall crop, sow by Aug 19.

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 111 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 3.6" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.9" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Madison County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~879 GDD — county provides 3,500 GDD Excellent fit

Kai Lan Planting Timeline — Madison County, TN

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors April 2 Apr 2 – Apr 16
Direct Sow March 19 Mar 19 – Apr 9
Harvest May 21 May 21 – Jun 18
Fall Sowing August 19 Aug 19 – Sep 2

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

209 days in Madison County

Growing Tips for Kai Lan in Madison County

Direct sow Kai Lan outdoors after April 02 in Madison County when soil has warmed and frost danger has passed.

Your generous 209.0-day season in Madison 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 Madison County, TN?

Madison County is in Zone 7b with an average last frost of April 2. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Madison County, TN?

Madison County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is October 28.

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Your Madison County Garden Planner — Free

A 24-page printable planner built for Madison County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Madison County, TN. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.