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When to Plant Kai Lan in Richland County, MT

Richland County, Montana Zone 4a May

Top priorities for Richland County, Montana gardeners in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 14
Avg. first frost September 20
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Move kai lan from tray to bed

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Outdoor sowing time: kai lan

    Your soil is 36°F — warm enough for these to germinate without babying.

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.

Richland County, Montana is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 20, giving you a growing season of approximately 129 days.

At an elevation of 6,414 feet, Richland County receives approximately 13.6 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Kai Lan to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Kai Lan successfully. Mulch heavily to conserve soil moisture.

Richland County, MT (Zone 4a) Short season
129 days
Last Spring Frost May 14
129 growing days
First Fall Frost September 20

Richland County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

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 0.9" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 4.3" 1.6" 2.7" 🚿 Regular watering
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 1" 3.3" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Richland County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Kai Lan Planting Timeline — Richland County, MT

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors May 14 May 14 – May 28
Direct Sow May 7 May 7 – May 28
Harvest July 2 Jul 2 – Jul 30
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

Moderate — regular watering

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

129 days in Richland County

Growing Tips for Richland County

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 Richland County, MT?

Richland County is in Zone 4a with an average last frost of May 14. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Richland County, MT?

Richland County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 20.

🌱

Your Richland County Garden Planner — Free

A 24-page printable planner built for Richland 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.

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 Richland County, MT. Local conditions may vary. Last updated: May 2026.

Sources & credits

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