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When to Plant Garlic in Mendocino County, CA

Mendocino County, California Zone 9b May

May in Mendocino County, California — your action list

Your Mendocino County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 23
Avg. first frost November 9
Soil temp (4") 71°F
Watering Critical
Pest pressure High
Daylight 14.2 hrs

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Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.

Mendocino County, California is in USDA Zone 9b. The average last spring frost is March 23 and the first fall frost is November 9, giving you a growing season of approximately 231 days.

At an elevation of 180 feet, Mendocino County receives approximately 24 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Garlic during the growing season. Sandy soil warms quickly in spring — great for early planting — but Garlic will need more frequent watering and organic matter to retain nutrients.

Mendocino County, CA (Zone 9b) Long season
231 days
Last Spring Frost March 23
231 growing days
First Fall Frost November 9
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Mendocino County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Monthly Watering Guide for Garlic

Garlic needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Garlic Needs Rainfall You Supplement Action
Jan 5.2" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 4.3" 3.7" 0.6" 💧 Light watering
Apr 4.3" 1.9" 2.4" 🚿 Regular watering
May 4.3" 0.6" 3.7" 🚿 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" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 1" 3.3" 🚿 Regular watering
Nov 4.3" 2.6" 1.7" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

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

Garlic Planting Timeline — Mendocino County, CA

Garlic Planting Calendar

Activity When Date Range
Fall Sowing September 28 Sep 28 – Oct 12

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August
September Fall Sowing
October Fall Sowing
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–240 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

231 days in Mendocino County

Growing Tips for Mendocino County

Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Garlic in Mendocino County, CA?

Mendocino County is in Zone 9b with an average last frost of March 23. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mendocino County, CA?

Mendocino County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 23 and first fall frost is November 9.

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Your Mendocino County Garden Planner — Free

A 24-page printable planner built for Mendocino County (Zone 9b). 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 Mendocino 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.