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When to Plant Kai Lan in Union County, MS

Union County, Mississippi Zone 8a May

What to do in May

A quick May briefing for Union County, Mississippi gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 30
Avg. first frost October 29
Soil temp (4") 70°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Get kai lan seeds going inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Harvest kai lan as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

A few tasks this May that'll pay off in June
  • 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.

Union County, Mississippi is in USDA Zone 8a. The average last spring frost is March 30 and the first fall frost is October 29, giving you a growing season of approximately 213 days.

At an elevation of 196 feet, Union County receives approximately 49.9 inches of rainfall annually with predominantly clay loam soil. Summer highs average 94°F, 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.

Union County, MS (Zone 8a) Long season
213 days
Last Spring Frost March 30
213 growing days
First Fall Frost October 29
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Union County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (142 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: May 9 – Jun 6
Recommended (50%) ✓ Fits season (136 days to spare)
Start indoors: Feb 23 Transplant: Mar 30 🍅 Harvest: May 18 – Jun 15
Safe Start (90%) ✓ Fits season (144 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 3 – Jul 1

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 Union County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Kai Lan's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). 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 213-day season

Sow every 5.1 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 20.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 30 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 3.8" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.3" 5.2" 0" ✅ Rainfall sufficient
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 5.1" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 3.6" 0" ❄️ Dormant
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Oct in Union 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 ~1,076 GDD — county provides 4,366 GDD Excellent fit

Kai Lan Planting Timeline — Union County, MS

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors March 30 Mar 30 – Apr 13
Direct Sow March 16 Mar 16 – Apr 6
Harvest May 18 May 18 – Jun 15
Fall Sowing August 20 Aug 20 – Sep 3

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors 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 8a

📆 Growing Season

213 days in Union County

Growing Tips for Kai Lan in Union County

Direct sow Kai Lan outdoors after March 30 in Union County when soil has warmed and frost danger has passed.

With Union County's clay soil (29% clay), work in 3-4 inches of compost before planting Kai Lan. Avoid tilling when soil is wet to prevent compaction.

Your generous 213.0-day season in Union 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 Union County, MS?

Union County is in Zone 8a with an average last frost of March 30. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, MS?

Union County, Mississippi is in USDA Hardiness Zone 8a. The average last spring frost is March 30 and first fall frost is October 29.

🌱

Your Union County Garden Planner — Free

A 24-page printable planner built for Union County (Zone 8a). 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 Union County, MS. 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.