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When to Plant Kai Lan in Douglas County, MO

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.

Douglas County, Missouri is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 758 feet, Douglas County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Kai Lan during the growing season.

Douglas County, MO (Zone 6b) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25

Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (119 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: May 23 – Jun 20
Recommended (50%) ✓ Fits season (122 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 28 – Jun 25
Safe Start (90%) ✓ Fits season (128 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 10 – Jul 8

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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 376 gal / 100 sq ft
Drought risk

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

Kai Lan needs ~879 GDD — county provides 3,333 GDD Excellent fit

Kai Lan Planting Timeline โ€” Douglas County, MO

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 โ€“ Mar 19
Transplant Outdoors April 9 Apr 9 โ€“ Apr 23
Direct Sow March 26 Mar 26 โ€“ Apr 16
Fall Sowing August 16 Aug 16 โ€“ Aug 30
Harvest May 28 May 28 โ€“ Jun 25

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 Harvest
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

199 days

Growing Tips for Douglas 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 Douglas County, MO?

Douglas County is in Zone 6b with an average last frost of April 9. Plan your Kai Lan planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Douglas County, MO?

Douglas County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Douglas 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 Douglas County, MO. Local conditions may vary. Last updated: April 2026.