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When to Plant Kai Lan in Marlboro County, SC

Marlboro County, South Carolina Zone 8a April

This month in Marlboro County, South Carolina

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

Avg. last frost March 23
Avg. first frost November 6
Soil temp (4") 62°F
Watering Moderate
Pest pressure High
Daylight 12.9 hrs
  1. Start kai lan indoors

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

May prep starts now
  • 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.

Marlboro County, South Carolina is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 6, giving you a growing season of approximately 228 days.

At an elevation of 132 feet, Marlboro County receives approximately 52.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kai Lan root diseases.

Marlboro County, SC (Zone 8a) Long season
228 days
Last Spring Frost March 23
228 growing days
First Fall Frost November 6
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Marlboro County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (154 days to spare)
Start indoors: Feb 9 Transplant: Mar 16 🍅 Harvest: May 4 – Jun 1
Recommended (50%) ✓ Fits season (151 days to spare)
Start indoors: Feb 16 Transplant: Mar 23 🍅 Harvest: May 11 – Jun 8
Safe Start (90%) ✓ Fits season (150 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 29 – Jun 26

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 Marlboro County

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

Soil pH

Your soil pH (5.7–6.5) overlaps with Kai Lan's range (6.0–7.5), though not a perfect match.

Soil Texture

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

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

6
successive plantings in your 228-day season

Sow every 5.1 weeks. Last sowing by Sep 07 to harvest before frost.

For a dedicated fall crop, sow by Aug 28.

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 59 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 4.6" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 4.3" 4.2" 0.1" 💧 Light watering
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 5.9" 0" ✅ Rainfall sufficient
Aug 4.3" 5.4" 0" ✅ Rainfall sufficient
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 3.9" 0.4" 💧 Light watering
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Marlboro 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 4,161 GDD Excellent fit

Kai Lan Planting Timeline — Marlboro County, SC

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 – Mar 2
Transplant Outdoors March 23 Mar 23 – Apr 6
Direct Sow March 9 Mar 9 – Mar 30
Harvest May 11 May 11 – Jun 8
Fall Sowing August 28 Aug 28 – Sep 11

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
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

228 days in Marlboro County

Growing Tips for Kai Lan in Marlboro County

Direct sow Kai Lan outdoors after March 23 in Marlboro County when soil has warmed and frost danger has passed.

With Marlboro County's clay soil (34% clay), work in 3-4 inches of compost before planting Kai Lan. Avoid tilling when soil is wet to prevent compaction.

Your generous 228.0-day season in Marlboro 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 Marlboro County, SC?

Marlboro County is in Zone 8a with an average last frost of March 23. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marlboro County, SC?

Marlboro County, South Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 6.

🌱

Your Marlboro County Garden Planner — Free

A 24-page printable planner built for Marlboro 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 Marlboro County, SC. 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.