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When to plant Mint in Keyes, CA

Plant Mint in Keyes, between March 3 and March 17 — the only viable window. Zone 9b's short season (278 frost-free days) rules out a fall crop.

When to Plant Mint in Keyes, CA

Mint
Stanislaus County, California Zone 9b June

Your June planting checklist for Stanislaus County, California

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

Avg. last frost February 24
Avg. first frost November 28
Soil temp (4") 80°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
  1. It's harvest week for mint

    If you can't use it all right away, check the food-preservation section of your planner.

Get ahead of July
  • 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.

Keyes, California is in USDA Zone 9b. 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 2,887 feet, Stanislaus County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94°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.

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

Keyes Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Mint 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 Keyes

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

Soil pH

Your soil pH (6.5–7.7) is more alkaline than Mint prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Stanislaus 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.

Mint Water Budget

Plant needs
0.7″/week
Rainfall provides
0.2″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,397 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 3.1" 0" ❄️ Dormant
Feb 3" 3.5" 0" ✅ Rainfall sufficient
Mar 3" 2.1" 0.9" 💧 Light watering
Apr 3" 1.3" 1.7" 🚿 Regular watering
May 3" 0.5" 2.5" 🚿 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" 1.5" 1.5" 🚿 Regular watering
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Stanislaus 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 ~1,538 GDD — county provides 5,699 GDD Excellent fit

Mint Planting Timeline — Keyes, 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 9b

📆 Growing Season

277 days in Stanislaus County

Growing Tips for Mint in Keyes

Direct sow Mint outdoors after February 24 in Stanislaus 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 →

When should I plant Mint in Keyes, CA?

In Keyes, CA, plant Mint after the last frost (around February 24) and before the first frost (around November 28). Best results when soil holds above 50°F.

What growing zone is Keyes, CA for Mint?

Keyes sits in USDA Zone 9b. Mint grows reliably in zones 3a through 10b, so it's a good fit here.

Can Mint grow in Keyes's climate?

Yes — Mint grows well in Keyes's temperate climate. Keyes averages a 278-day frost-free season, with last frost around February 24 and first frost around November 28.

🌱

Your Stanislaus County Garden Planner — Free

A 22-page printable planner built for Stanislaus 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 Stanislaus County, CA. Local conditions may vary. Last updated: June 2026.