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When to Plant Lemongrass in Los Angeles County, CA

Los Angeles County, California Zone 10b May

Your May game plan for Los Angeles County, California

Each item below is timed to Los Angeles County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 3
Avg. first frost November 21
Soil temp (4") 80°F
Watering Critical
Pest pressure High
Daylight 13.8 hrs
  1. Get lemongrass seeds going inside

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

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

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Lemongrass is a tropical grass with a strong citrus aroma used extensively in Southeast Asian cuisine. The swollen stem bases are the most flavorful part.

Los Angeles County, California is in USDA Zone 10b. The average last spring frost is April 3 and the first fall frost is November 21, giving you a growing season of approximately 232 days.

At an elevation of 1,315 feet, Los Angeles County receives approximately 12.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Lemongrass during the growing season. With low rainfall, drip irrigation is essential for growing Lemongrass successfully. Mulch heavily to conserve soil moisture.

Los Angeles County, CA (Zone 10b) Long season
232 days
Last Spring Frost April 3
232 growing days
First Fall Frost November 21
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Los Angeles County Soil Profile

Soil Type

Loam

Soil pH

5.8-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Start indoors: Jan 23 Transplant: Mar 13 🍅 Harvest: May 29 – Aug 28
Recommended (50%) ✓ Fits season (57 days to spare)
Start indoors: Feb 20 Transplant: Apr 10 🍅 Harvest: Jun 26 – Sep 25
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: Apr 16 Transplant: Jun 4 🍅 Harvest: Aug 20 – Nov 19

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 Los Angeles County

How your county's soil matches Lemongrass's growing requirements.

Soil pH

Your soil pH (5.8–7.5) is within Lemongrass's preferred range (5.5–7.5).

Soil Texture

The loam soil in Los Angeles County is excellent for Lemongrass — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Lemongrass.

How to Plant Lemongrass

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Lemongrass

3
successive plantings in your 232-day season

Sow every 8.6 weeks. Last sowing by Jul 24 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.2″/week
You supply
1.5″/week
Watering frequency 2-3 times/week
Season total 3,138 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Lemongrass

Lemongrass needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Lemongrass Needs Rainfall You Supplement Action
Jan 2.4" 0" ❄️ Dormant
Feb 2.5" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 6.5" 1.2" 5.3" 🚿 Regular watering
May 6.5" 0.4" 6.1" 🚿 Regular watering
Jun 6.5" 0.1" 6.4" 🚿 Regular watering
Jul 6.5" 0" 6.5" 🚿 Regular watering
Aug 6.5" 0" 6.5" 🚿 Regular watering
Sep 6.5" 0.2" 6.3" 🚿 Regular watering
Oct 6.5" 0.6" 5.9" 🚿 Regular watering
Nov 6.5" 1.3" 5.2" 🚿 Regular watering
Dec 2.1" 0" ❄️ Dormant

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

Lemongrass 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.

Lemongrass needs ~1,487 GDD — county provides 3,538 GDD Excellent fit

Lemongrass Planting Timeline — Los Angeles County, CA

Lemongrass Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow April 10 Apr 10 – May 1
Harvest June 26 Jun 26 – Sep 25

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

75–120 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 10b

📆 Growing Season

232 days in Los Angeles County

Growing Tips for Lemongrass in Los Angeles County

Direct sow Lemongrass outdoors after April 03 in Los Angeles County when soil has warmed and frost danger has passed.

Common pests for Lemongrass in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

Los Angeles County receives only 13" of rain annually. Lemongrass needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start from divisions or store-bought stalks rooted in water. Grow in rich, moist soil with full sun. In cold climates, grow in containers and overwinter indoors.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lemongrass in Los Angeles County, CA?

Los Angeles County is in Zone 10b with an average last frost of April 3. Plan your Lemongrass planting based on this frost date — see the calendar above for exact timing.

What planting zone is Los Angeles County, CA?

Los Angeles County, California is in USDA Hardiness Zone 10b. The average last spring frost is April 3 and first fall frost is November 21.

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Your Los Angeles County Garden Planner — Free

A 24-page printable planner built for Los Angeles County (Zone 10b). 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 Los Angeles 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.