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When to Plant Lemongrass in Santa Barbara County, CA

Santa Barbara County, California Zone 10a May

Your May gardening checklist

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

Avg. last frost February 28
Avg. first frost November 24
Soil temp (4") 73°F
Watering Critical
Pest pressure High
Daylight 13.8 hrs
  1. It's harvest week for lemongrass

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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.

Santa Barbara County, California is in USDA Zone 10a. The average last spring frost is February 28 and the first fall frost is November 24, giving you a growing season of approximately 269 days.

At an elevation of 2,364 feet, Santa Barbara County receives approximately 19.9 inches of rainfall annually with predominantly loam soil. Summer highs average 89°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.

Santa Barbara County, CA (Zone 10a) Long season
269 days
Last Spring Frost February 28
269 growing days
First Fall Frost November 24

Santa Barbara County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (98 days to spare)
Start indoors: Jan 1 Transplant: Feb 19 🍅 Harvest: May 7 – Aug 6
Recommended (50%) ✓ Fits season (94 days to spare)
Start indoors: Jan 17 Transplant: Mar 7 🍅 Harvest: May 23 – Aug 22
Safe Start (90%) ✓ Fits season (82 days to spare)
Start indoors: Feb 24 Transplant: Apr 14 🍅 Harvest: Jun 30 – Sep 29

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 Santa Barbara County

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

Soil pH

Your soil pH (6.5–7.2) is within Lemongrass's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Lemongrass.

How to Plant Lemongrass

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

Succession Planting Lemongrass

4
successive plantings in your 269-day season

Sow every 8.6 weeks. Last sowing by Jul 27 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.3″/week
You supply
1.4″/week
Watering frequency 2-3 times/week
Season total 3,433 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 4" 0" ❄️ Dormant
Feb 6.5" 4.6" 1.9" 💧 Light watering
Mar 6.5" 2.9" 3.6" 🚿 Regular watering
Apr 6.5" 1.8" 4.7" 🚿 Regular watering
May 6.5" 0.5" 6" 🚿 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" 0.8" 5.7" 🚿 Regular watering
Nov 6.5" 2.1" 4.4" 🚿 Regular watering
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Santa Barbara 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 ~1,633 GDD — county provides 4,522 GDD Excellent fit

Lemongrass Planting Timeline — Santa Barbara County, CA

Lemongrass Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors March 7 Mar 7 – Mar 21
Direct Sow March 7 Mar 7 – Mar 28
Harvest May 23 May 23 – Aug 22

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

Month-by-Month Timeline

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

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 10a

📆 Growing Season

269 days in Santa Barbara County

Growing Tips for Lemongrass in Santa Barbara County

Direct sow Lemongrass outdoors after February 28 in Santa Barbara 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.

Santa Barbara County receives only 20" 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 Santa Barbara County, CA?

Santa Barbara County is in Zone 10a with an average last frost of February 28. Plan your Lemongrass planting based on this frost date — see the calendar above for exact timing.

What planting zone is Santa Barbara County, CA?

Santa Barbara County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 28 and first fall frost is November 24.

🌱

Your Santa Barbara County Garden Planner — Free

A 24-page printable planner built for Santa Barbara County (Zone 10a). 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 Santa Barbara 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.