Blog

When to Plant Kai Lan in Rockland County, NY

Rockland County, New York Zone 7a May

Your May game plan for Rockland County, New York

We've pulled the most time-sensitive tasks for Rockland County, New York this May and put them front and centre. Tackle them in order.

Avg. last frost March 29
Avg. first frost November 12
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Start kai lan under lights

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. Collect kai lan at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Coming up in June — start thinking about
  • First harvests: kai lan

Instant PDF download. No spam, unsubscribe any time.

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.

Rockland County, New York is in USDA Zone 7a. The average last spring frost is March 29 and the first fall frost is November 12, giving you a growing season of approximately 228 days.

At an elevation of 746 feet, Rockland County receives approximately 43.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Kai Lan during the growing season.

Rockland County, NY (Zone 7a) Long season
228 days
Last Spring Frost March 29
228 growing days
First Fall Frost November 12

Rockland County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (151 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 13 – Jun 10
Recommended (50%) ✓ Fits season (151 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: May 17 – Jun 14
Safe Start (90%) ✓ Fits season (160 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 28 – Jun 25

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 Rockland County

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Kai Lan prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Rockland 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 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 13 to harvest before frost.

For a dedicated fall crop, sow by Sep 03.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 392 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 3.2" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.3" 4.1" 0.2" 💧 Light watering
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 2.8" 1.5" 💧 Light watering
Dec 2.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Rockland 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 ~840 GDD — county provides 3,648 GDD Excellent fit

Kai Lan Planting Timeline — Rockland County, NY

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors March 29 Mar 29 – Apr 12
Direct Sow March 15 Mar 15 – Apr 5
Harvest May 17 May 17 – Jun 14
Fall Sowing September 3 Sep 3 – Sep 17

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
September Fall Sowing
October
November
December

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: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

228 days in Rockland County

Growing Tips for Kai Lan in Rockland County

Direct sow Kai Lan outdoors after March 29 in Rockland County when soil has warmed and frost danger has passed.

Your generous 228.0-day season in Rockland 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 Rockland County, NY?

Rockland County is in Zone 7a with an average last frost of March 29. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rockland County, NY?

Rockland County, New York is in USDA Hardiness Zone 7a. The average last spring frost is March 29 and first fall frost is November 12.

🌱

Your Rockland County Garden Planner — Free

A 24-page printable planner built for Rockland County (Zone 7a). 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 Rockland County, NY. 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.