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When to Plant Kai Lan in Johnson County, TN

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.

Johnson County, Tennessee is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 22, giving you a growing season of approximately 191 days.

At an elevation of 404 feet, Johnson County receives approximately 43.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Kai Lan during the growing season.

Johnson County, TN (Zone 6b) Moderate season
191 days
Last Spring Frost April 14
191 growing days
First Fall Frost October 22

Johnson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (114 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 28 – Jun 25
Recommended (50%) ✓ Fits season (114 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: Jun 2 – Jun 30
Safe Start (90%) ✓ Fits season (107 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jun 22 – Jul 20

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 102 gal / 100 sq ft
Drought risk

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

Kai Lan needs ~761 GDD — county provides 2,769 GDD Excellent fit

Kai Lan Planting Timeline โ€” Johnson County, TN

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 14 Apr 14 โ€“ Apr 28
Direct Sow March 31 Mar 31 โ€“ Apr 21
Fall Sowing August 13 Aug 13 โ€“ Aug 27
Harvest June 2 Jun 2 โ€“ Jun 30

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

45โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

191 days

Growing Tips for Johnson 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Kai Lan in Johnson County, TN?

Johnson County is in Zone 6b with an average last frost of April 14. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Johnson County, TN?

Johnson County, Tennessee is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

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