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When to Plant Mint in San Juan County, NM

San Juan County, New Mexico Zone 7a May

This month in San Juan County, New Mexico

A quick May briefing for San Juan County, New Mexico gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 12
Avg. first frost October 6
Soil temp (4") 32°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Move mint from tray to bed

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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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.

San Juan County, New Mexico is in USDA Zone 7a. The average last spring frost is May 12 and the first fall frost is October 6, giving you a growing season of approximately 147 days.

At an elevation of 8,301 feet, San Juan County receives approximately 14.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Mint during the growing season. Sandy soil warms quickly in spring — great for early planting — but Mint will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Mint successfully. Mulch heavily to conserve soil moisture.

San Juan County, NM (Zone 7a) Short season
147 days
Last Spring Frost May 12
147 growing days
First Fall Frost October 6
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San Juan County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Transplant: May 12 🍅 Harvest: Jul 14 – Sep 22
Recommended (50%) ✓ Fits season (7 days to spare)
Transplant: May 19 🍅 Harvest: Jul 21 – Sep 29
Safe Start (90%) ✓ Fits season (1 days to spare)
Transplant: Jun 9 🍅 Harvest: Aug 11 – Oct 20

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 San Juan County

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

Soil pH

Your soil pH (7.3–8.5) is more alkaline than Mint prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in San Juan County warms quickly in spring but drains fast. Mint will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Mint is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Mint.

How to Plant Mint

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

Succession Planting Mint

2
successive plantings in your 147-day season

Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.4″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 787 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 1.1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 0.5" 0" ❄️ Dormant
May 3" 0.3" 2.7" 🚿 Regular watering
Jun 3" 0.5" 2.5" 🚿 Regular watering
Jul 3" 2.5" 0.5" 💧 Light watering
Aug 3" 2.6" 0.4" 💧 Light watering
Sep 3" 2.2" 0.8" 💧 Light watering
Oct 3" 1.3" 1.7" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in San Juan 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 2,241 GDD Excellent fit

Mint Planting Timeline — San Juan County, NM

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 19 May 19 – Jun 2
Harvest July 21 Jul 21 – Sep 29

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October
November
December
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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 7a

📆 Growing Season

147 days in San Juan County

Growing Tips for Mint in San Juan County

Direct sow Mint outdoors after May 12 in San Juan County when soil has warmed and frost danger has passed.

Sandy soil in San Juan County dries quickly — mulch Mint with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 San Juan County, NM?

San Juan County is in Zone 7a with an average last frost of May 12. Plan your Mint planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Juan County, NM?

San Juan County, New Mexico is in USDA Hardiness Zone 7a. The average last spring frost is May 12 and first fall frost is October 6.

🌱

Your San Juan County Garden Planner — Free

A 24-page printable planner built for San Juan County (Zone 7a). 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 San Juan County, NM. 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.