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When to Plant Mint in Merced County, CA

Merced County, California Zone 9a May

This month in Merced County, California

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

Avg. last frost February 24
Avg. first frost November 28
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Bring in the mint

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

To set up a strong June, finish these tasks
  • First harvests: mint

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Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.

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 Mint during the growing season. With low rainfall, drip irrigation is essential for growing Mint 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 (149 days to spare)
Transplant: Feb 13 🍅 Harvest: Apr 17 – Jun 26
Recommended (50%) ✓ Fits season (137 days to spare)
Transplant: Mar 3 🍅 Harvest: May 5 – Jul 14
Safe Start (90%) ✓ Fits season (102 days to spare)
Transplant: Apr 25 🍅 Harvest: Jun 27 – Sep 5

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 Mint's growing requirements.

Soil pH

Your soil pH (6.8–7.7) is more alkaline than Mint prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

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

How to Plant Mint

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

Succession Planting Mint

5
successive plantings in your 277-day season

Sow every 6.9 weeks. Last sowing by Aug 30 to harvest before frost.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.3″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,235 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Mint

Mint needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Mint Needs Rainfall You Supplement Action
Jan 4.4" 0" ❄️ Dormant
Feb 3" 4" 0" ✅ Rainfall sufficient
Mar 3" 2.6" 0.4" 💧 Light watering
Apr 3" 1.7" 1.3" 💧 Light watering
May 3" 0.4" 2.6" 🚿 Regular watering
Jun 3" 0.1" 2.9" 🚿 Regular watering
Jul 3" 0" 3" 🚿 Regular watering
Aug 3" 0" 3" 🚿 Regular watering
Sep 3" 0.2" 2.8" 🚿 Regular watering
Oct 3" 0.7" 2.3" 🚿 Regular watering
Nov 3" 1.6" 1.4" 💧 Light watering
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.

Mint 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.

Mint needs ~1,144 GDD — county provides 4,239 GDD Excellent fit

Mint Planting Timeline — Merced County, CA

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors March 3 Mar 3 – Mar 17
Harvest May 5 May 5 – Jul 14

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Merced County

Growing Tips for Mint in Merced County

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

General growing tips

Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.

Companion Planting

Good Companions

Avoid Planting Near

  • Parsley

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mint in Merced County, CA?

Merced County is in Zone 9a with an average last frost of February 24. Plan your Mint 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.