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When to Plant Lavender in Merced County, CA

Merced County, California Zone 9a May

May in Merced County, California — your action list

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Merced County, California.

Avg. last frost February 24
Avg. first frost November 28
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14 hrs
A few tasks this May that'll pay off in June
  • First harvests: lavender

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Lavender is a fragrant perennial herb with silvery foliage and purple flower spikes. It is prized for its essential oils, culinary uses, and ornamental beauty.

Merced County, California is in USDA Zone 9a. The average last spring frost is February 24 and the first fall frost is November 28, giving you a growing season of approximately 277 days.

At an elevation of 269 feet, Merced County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Lavender during the growing season. With low rainfall, drip irrigation is essential for growing Lavender successfully. Mulch heavily to conserve soil moisture.

Merced County, CA (Zone 9a) Year-round
277 days
Last Spring Frost February 24
277 growing days
First Fall Frost November 28

Merced County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Transplant: Feb 13 🍅 Harvest: May 15 – Oct 16
Recommended (50%) ✓ Fits season (25 days to spare)
Transplant: Mar 3 🍅 Harvest: Jun 2 – Nov 3
Safe Start (90%) ✗ May not fit
Transplant: Apr 25 🍅 Harvest: Jul 25 – Dec 26

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 Merced County

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

Soil pH

Your soil pH (6.8–7.7) is within Lavender's preferred range (6.5–8.0).

Soil Texture

The loam soil in Merced County is excellent for Lavender — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Lavender.

How to Plant Lavender

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

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.3″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 47 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Lavender

Lavender needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Lavender Needs Rainfall You Supplement Action
Jan 4.4" 0" ❄️ Dormant
Feb 1.3" 4" 0" ✅ Rainfall sufficient
Mar 1.3" 2.6" 0" ✅ Rainfall sufficient
Apr 1.3" 1.7" 0" ✅ Rainfall sufficient
May 1.3" 0.4" 0.9" 🚿 Regular watering
Jun 1.3" 0.1" 1.2" 🚿 Regular watering
Jul 1.3" 0" 1.3" 🚿 Regular watering
Aug 1.3" 0" 1.3" 🚿 Regular watering
Sep 1.3" 0.2" 1.1" 🚿 Regular watering
Oct 1.3" 0.7" 0.6" 💧 Light watering
Nov 1.3" 1.6" 0" ✅ Rainfall sufficient
Dec 3.1" 0" ❄️ Dormant

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

Lavender 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.

Lavender needs ~2,211 GDD — county provides 4,239 GDD Excellent fit

Lavender Planting Timeline — Merced County, CA

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors March 3 Mar 3 – Mar 17
Harvest June 2 Jun 2 – Nov 3

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Only during dry spells

📅 Days to Maturity

90–200 days

🧪 Soil pH

Needs 6.5–8 · Your soil: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Merced County

Growing Tips for Lavender in Merced County

Direct sow Lavender outdoors after February 24 in Merced County when soil has warmed and frost danger has passed.

General growing tips

Plant in well-drained, sandy soil. Avoid heavy mulching around the crown. Prune after flowering but do not cut into old wood. Lavender resents wet winter conditions.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Merced County, CA?

Merced County is in Zone 9a with an average last frost of February 24. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Merced County, CA?

Merced County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 24 and first fall frost is November 28.

🌱

Your Merced County Garden Planner — Free

A 24-page printable planner built for Merced 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 Merced 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.