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When to Plant Kai Lan in Nevada County, CA

Nevada County, California Zone 9a May

Nevada County, California gardeners: here's your May plan

May is a pivotal month for Nevada County, California gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 10
Avg. first frost October 22
Soil temp (4") 63°F
Watering High
Pest pressure Moderate
Daylight 14.2 hrs
  1. Transplant kai lan outside

    Frost risk is low now in Nevada County, California. If you've been covering beds overnight, you can stop.

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

Nevada County, California is in USDA Zone 9a. The average last spring frost is May 10 and the first fall frost is October 22, giving you a growing season of approximately 165 days.

At an elevation of 2,745 feet, Nevada County receives approximately 44.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Kai Lan to ensure they mature before fall.

Nevada County, CA (Zone 9a) Moderate season
165 days
Last Spring Frost May 10
165 growing days
First Fall Frost October 22
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Nevada County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Start indoors: Mar 28 Transplant: Apr 25 🍅 Harvest: Jun 13 – Jul 11
Recommended (50%) ✓ Fits season (88 days to spare)
Start indoors: Apr 12 Transplant: May 10 🍅 Harvest: Jun 28 – Jul 26
Safe Start (90%) ✓ Fits season (96 days to spare)
Start indoors: May 8 Transplant: Jun 5 🍅 Harvest: Jul 24 – Aug 21

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 Nevada County

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

Soil pH

Your soil pH (6.8–7.5) is within Kai Lan's preferred range (6.0–7.5).

Soil Texture

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

Drainage

Drainage is adequate for Kai Lan.

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 8 weeks before your first frost date for a fall harvest.

Succession Planting Kai Lan

4
successive plantings in your 165-day season

Sow every 5.1 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 27.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 286 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 9.9" 0" ❄️ Dormant
Feb 8.7" 0" ❄️ Dormant
Mar 7.9" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.4" 3.9" 🚿 Regular watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 4.6" 0" ❄️ Dormant
Dec 6.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Nevada 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 ~643 GDD — county provides 2,021 GDD Excellent fit

Kai Lan Planting Timeline — Nevada County, CA

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors April 12 Apr 12 – Apr 26
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 19 Apr 19 – May 10
Harvest June 28 Jun 28 – Jul 26
Fall Sowing August 27 Aug 27 – Sep 10

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
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: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

165 days in Nevada County

Growing Tips for Kai Lan in Nevada County

Direct sow Kai Lan outdoors after May 10 in Nevada County when soil has warmed and frost danger has passed.

Your generous 165.0-day season in Nevada 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 Nevada County, CA?

Nevada County is in Zone 9a with an average last frost of May 10. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Nevada County, CA?

Nevada County, California is in USDA Hardiness Zone 9a. The average last spring frost is May 10 and first fall frost is October 22.

🌱

Your Nevada County Garden Planner — Free

A 24-page printable planner built for Nevada County (Zone 9a). 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 Nevada County, CA. 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.