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When to Plant Mint in Rich County, UT

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

Rich County, Utah is in USDA Zone 4b. The average last spring frost is May 31 and the first fall frost is September 15, giving you a growing season of approximately 107 days.

At an elevation of 5,803 feet, Rich County receives approximately 18 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Mint to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Mint successfully. Mulch heavily to conserve soil moisture.

Rich County, UT (Zone 4b) Short season
107 days
Last Spring Frost May 31
107 growing days
First Fall Frost September 15

Rich County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 21 🍅 Harvest: Jul 23 – Oct 1
Recommended (50%) ✗ May not fit
Transplant: Jun 7 🍅 Harvest: Aug 9 – Oct 18
Safe Start (90%) ✗ May not fit
Transplant: Jun 29 🍅 Harvest: Aug 31 – Nov 9

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 Rich County

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

Soil pH

Your soil pH (6.5โ€“8.2) is more alkaline than Mint prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Rich County is excellent for Mint โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Mint.

How to Plant Mint

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

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” 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 โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.1" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr โ€” 2" 0" โ„๏ธ Dormant
May 3" 1.9" 1.1" ๐Ÿ’ง Light watering
Jun 3" 1.4" 1.6" ๐Ÿšฟ Regular watering
Jul 3" 1.7" 1.3" ๐Ÿ’ง Light watering
Aug 3" 1.7" 1.3" ๐Ÿ’ง Light watering
Sep 3" 1.4" 1.6" ๐Ÿšฟ Regular watering
Oct โ€” 1.6" 0" โ„๏ธ Dormant
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Rich County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~806 GDD — county provides 1,150 GDD Excellent fit

Mint Planting Timeline โ€” Rich County, UT

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors June 7 Jun 7 โ€“ Jun 21
Harvest August 9 Aug 9 โ€“ Oct 18

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

107 days in Rich County

Growing Tips for Mint in Rich County

Direct sow Mint outdoors after May 31 in Rich 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 Rich County, UT?

Rich County is in Zone 4b with an average last frost of May 31. Plan your Mint planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Rich County, UT?

Rich County, Utah is in USDA Hardiness Zone 4b. The average last spring frost is May 31 and first fall frost is September 15.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Rich County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Rich County, UT. Local conditions may vary. Last updated: April 2026.