Blog

When to Plant Kai Lan in St. Francois County, MO

St. Francois County, Missouri Zone 6b April

April to-do list for St. Francois County, Missouri

Your St. Francois County, Missouri garden is entering a new phase. Here's what's on the schedule for April and why each task matters now.

Avg. last frost April 16
Avg. first frost October 21
Soil temp (4") 53°F
Watering Low
Pest pressure Low
Daylight 13 hrs
  1. Get kai lan in the ground

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Seed kai lan outdoors

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

Coming up in May — start thinking about
  • Starting indoors: kai lan

Instant PDF download. No spam, unsubscribe any time.

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.

St. Francois County, Missouri is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 21, giving you a growing season of approximately 188 days.

At an elevation of 808 feet, St. Francois County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Kai Lan during the growing season.

St. Francois County, MO (Zone 6b) Moderate season
188 days
Last Spring Frost April 16
188 growing days
First Fall Frost October 21

St. Francois 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 (111 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: May 27 – Jun 24
Recommended (50%) ✓ Fits season (111 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 4 – Jul 2
Safe Start (90%) ✓ Fits season (113 days to spare)
Start indoors: Mar 25 Transplant: Apr 29 🍅 Harvest: Jun 17 – Jul 15

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 St. Francois 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 St. Francois County is excellent for Kai Lan — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Kai Lan.

Organic Matter

Organic matter is moderate (2.9%). 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

4
successive plantings in your 188-day season

Sow every 5.1 weeks. Last sowing by Aug 22 to harvest before frost.

For a dedicated fall crop, sow by Aug 12.

Plant Water Budget

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

Water stress score is 6/10 — 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 1.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 5.4" 0" ✅ Rainfall sufficient
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in St. Francois 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 ~958 GDD — county provides 3,431 GDD Excellent fit

Kai Lan Planting Timeline — St. Francois County, MO

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 2 Apr 2 – Apr 23
Harvest June 4 Jun 4 – Jul 2
Fall Sowing August 12 Aug 12 – Aug 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

188 days in St. Francois County

Growing Tips for Kai Lan in St. Francois County

Direct sow Kai Lan outdoors after April 16 in St. Francois County when soil has warmed and frost danger has passed.

Your generous 188.0-day season in St. Francois 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 St. Francois County, MO?

St. Francois County is in Zone 6b with an average last frost of April 16. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Francois County, MO?

St. Francois County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 21.

🌱

Your St. Francois County Garden Planner — Free

A 24-page printable planner built for St. Francois County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for St. Francois County, MO. Local conditions may vary. Last updated: April 2026.

Sources & credits

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