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When to Plant Kai Lan in Randolph County, AR

Randolph County, Arkansas Zone 7b May

Your May gardening checklist

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Randolph County, Arkansas.

Avg. last frost March 27
Avg. first frost November 2
Soil temp (4") 67°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Start kai lan under lights

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Bring in the kai lan

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

June will be here before you know it — start on
  • 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.

Randolph County, Arkansas is in USDA Zone 7b. The average last spring frost is March 27 and the first fall frost is November 2, giving you a growing season of approximately 220 days.

At an elevation of 308 feet, Randolph County receives approximately 52.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Kai Lan during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kai Lan root diseases.

Randolph County, AR (Zone 7b) Long season
220 days
Last Spring Frost March 27
220 growing days
First Fall Frost November 2
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Randolph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (146 days to spare)
Start indoors: Feb 12 Transplant: Mar 19 🍅 Harvest: May 7 – Jun 4
Recommended (50%) ✓ Fits season (143 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: May 15 – Jun 12
Safe Start (90%) ✓ Fits season (143 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 4 – Jul 2

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 Randolph County

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

Soil pH

Your soil pH (5.5–6.7) overlaps with Kai Lan's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Randolph 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

5
successive plantings in your 220-day season

Sow every 5.1 weeks. Last sowing by Sep 03 to harvest before frost.

For a dedicated fall crop, sow by Aug 24.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Only during dry spells
Season total 7 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 3.8" 0" ❄️ Dormant
Mar 4.3" 5.1" 0" ✅ Rainfall sufficient
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.2" 0" ✅ Rainfall sufficient
Sep 4.3" 4.4" 0" ✅ Rainfall sufficient
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 4.3" 4.1" 0.2" 💧 Light watering
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Randolph 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 ~1,037 GDD — county provides 4,345 GDD Excellent fit

Kai Lan Planting Timeline — Randolph County, AR

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 13 Mar 13 – Apr 3
Harvest May 15 May 15 – Jun 12
Fall Sowing August 24 Aug 24 – Sep 7

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 7b

📆 Growing Season

220 days in Randolph County

Growing Tips for Kai Lan in Randolph County

Direct sow Kai Lan outdoors after March 27 in Randolph County when soil has warmed and frost danger has passed.

Your generous 220.0-day season in Randolph 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 Randolph County, AR?

Randolph County is in Zone 7b with an average last frost of March 27. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Randolph County, AR?

Randolph County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is March 27 and first fall frost is November 2.

🌱

Your Randolph County Garden Planner — Free

A 24-page printable planner built for Randolph County (Zone 7b). 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 Randolph County, AR. Local conditions may vary. Last updated: May 2026.

Sources & credits

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