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When to Plant Cantaloupe in San Juan County, UT

Cantaloupe is a sweet, aromatic melon with salmon-colored flesh and a netted rind. It requires a long, warm growing season and is the quintessential summer fruit.

San Juan County, Utah is in USDA Zone 5b. The average last spring frost is May 2 and the first fall frost is October 11, giving you a growing season of approximately 162 days.

At an elevation of 5,225 feet, San Juan County receives approximately 13.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Cantaloupe to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cantaloupe successfully. Mulch heavily to conserve soil moisture.

San Juan County, UT (Zone 5b) Moderate season
162 days
Last Spring Frost May 2
162 growing days
First Fall Frost October 11

San Juan County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Transplant: May 11 🍅 Harvest: Jul 20 – Aug 24
Recommended (50%) ✓ Fits season (36 days to spare)
Transplant: May 23 🍅 Harvest: Aug 1 – Sep 5
Safe Start (90%) ✓ Fits season (29 days to spare)
Transplant: Jun 16 🍅 Harvest: Aug 25 – Sep 29

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 Cantaloupe's growing requirements.

Soil pH

Your soil pH (6.5โ€“7.8) is more alkaline than Cantaloupe prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Cantaloupe.

How to Plant Cantaloupe

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Cantaloupe

2
successive plantings in your 162-day season

Sow every 8 weeks. Last sowing by Jul 13 to harvest before frost.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.4″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,635 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cantaloupe

Cantaloupe needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Cantaloupe Needs Rainfall You Supplement Action
Jan โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.9" 0" โ„๏ธ Dormant
Mar โ€” 1.1" 0" โ„๏ธ Dormant
Apr โ€” 1.3" 0" โ„๏ธ Dormant
May 5.6" 1.6" 4" ๐Ÿšฟ Regular watering
Jun 5.6" 1" 4.6" ๐Ÿšฟ Regular watering
Jul 5.6" 1" 4.6" ๐Ÿšฟ Regular watering
Aug 5.6" 1.6" 4" ๐Ÿšฟ Regular watering
Sep 5.6" 1.2" 4.4" ๐Ÿšฟ Regular watering
Oct 5.6" 1.2" 4.4" ๐Ÿšฟ Regular watering
Nov โ€” 0.9" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in San Juan County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Cantaloupe 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.

Cantaloupe needs ~1,040 GDD — county provides 2,106 GDD Excellent fit

Cantaloupe Planting Timeline โ€” San Juan County, UT

Cantaloupe Planting Calendar

Activity When Date Range
Transplant Outdoors May 23 May 23 โ€“ Jun 6
Harvest August 1 Aug 1 โ€“ Sep 5

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.3"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

70โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

162 days in San Juan County

Growing Tips for Cantaloupe in San Juan County

Direct sow Cantaloupe outdoors after May 02 in San Juan County when soil has warmed and frost danger has passed.

Common pests for Cantaloupe in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

San Juan County receives only 14" of rain annually. Cantaloupe needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 3-4 weeks early or direct sow on warm mounds. Reduce watering as fruits ripen. Harvest when stem slips easily from the fruit with gentle pressure.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cantaloupe in San Juan County, UT?

San Juan County is in Zone 5b with an average last frost of May 2. Plan your Cantaloupe planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Juan County, UT?

San Juan County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is May 2 and first fall frost is October 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Juan County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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, UT. Local conditions may vary. Last updated: April 2026.