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When to Plant Kai Lan in Divide County, ND

Divide County, North Dakota Zone 4a May

This month in Divide County, North Dakota

Your garden in Divide County, North Dakota is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 15
Avg. first frost September 20
Soil temp (4") 52°F
Watering Moderate
Pest pressure Low
Daylight 15 hrs
  1. Transplant kai lan outside

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Put kai lan seeds straight in the ground

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

A few tasks this May that'll pay off in June
  • Starting indoors: kai lan
  • Fall sowing: 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.

Divide County, North Dakota is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is September 20, giving you a growing season of approximately 128 days.

At an elevation of 994 feet, Divide County receives approximately 20.5 inches of rainfall annually with predominantly loam soil. Summer highs average 79°F, so choose short-season varieties of Kai Lan to ensure they mature before fall.

Divide County, ND (Zone 4a) Short season
128 days
Last Spring Frost May 15
128 growing days
First Fall Frost September 20

Divide County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jun 30 – Jul 28
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 3 – Jul 31
Safe Start (90%) ✓ Fits season (54 days to spare)
Start indoors: Apr 15 Transplant: May 27 🍅 Harvest: Jul 15 – Aug 12

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 Divide County

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

Soil pH

Your soil pH (6.2–7.6) overlaps with Kai Lan's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). 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 12 weeks before your first frost date for a fall harvest.

Succession Planting Kai Lan

3
successive plantings in your 128-day season

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

For a dedicated fall crop, sow by Jun 28.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 447 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Divide 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 ~486 GDD — county provides 1,184 GDD Excellent fit

Kai Lan Planting Timeline — Divide County, ND

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 8 May 8 – May 29
Harvest July 3 Jul 3 – Jul 31
Fall Sowing June 28 Jun 28 – Jul 12

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

128 days in Divide County

Growing Tips for Kai Lan in Divide County

Direct sow Kai Lan outdoors after May 15 in Divide County when soil has warmed and frost danger has passed.

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.

Divide County receives only 20" of rain annually. Kai Lan needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Divide County, ND?

Divide County is in Zone 4a with an average last frost of May 15. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Divide County, ND?

Divide County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is September 20.

🌱

Your Divide County Garden Planner — Free

A 24-page printable planner built for Divide County (Zone 4a). 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 Divide County, ND. Local conditions may vary. Last updated: May 2026.

Sources & credits

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