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When to Plant Melon in Lemhi County, ID

Melons are warm-season vine crops that produce sweet, juicy fruits in many varieties including muskmelon and honeydew. They need a long, hot growing season.

Lemhi County, Idaho is in USDA Zone 4b. The average last spring frost is June 9 and the first fall frost is September 14, giving you a growing season of approximately 97 days.

At an elevation of 6,743 feet, Lemhi County receives approximately 12.6 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Melon to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Melon successfully. Mulch heavily to conserve soil moisture.

Lemhi County, ID (Zone 4b) Very short season
97 days
Last Spring Frost June 9
97 growing days
First Fall Frost September 14

Lemhi County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 2 Transplant: Jun 4 🍅 Harvest: Aug 13 – Oct 1
Recommended (50%) ✗ May not fit
Start indoors: Apr 28 Transplant: Jun 30 🍅 Harvest: Sep 8 – Oct 27
Safe Start (90%) ✗ May not fit
Start indoors: May 14 Transplant: Jul 16 🍅 Harvest: Sep 24 – Nov 12

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 Lemhi County

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

Soil pH

Your soil pH (6.2โ€“8.2) is more alkaline than Melon prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Melon.

How to Plant Melon

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 471 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Melon

Melon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Melon Needs Rainfall You Supplement Action
Jan โ€” 0.8" 0" โ„๏ธ Dormant
Feb โ€” 0.9" 0" โ„๏ธ Dormant
Mar โ€” 1" 0" โ„๏ธ Dormant
Apr โ€” 1.3" 0" โ„๏ธ Dormant
May โ€” 1.4" 0" โ„๏ธ Dormant
Jun 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Jul 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Aug 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Sep 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Oct โ€” 1" 0" โ„๏ธ Dormant
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

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

Melon 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.

Melon needs ~1,105 GDD — county provides 1,261 GDD Good fit

Melon Planting Timeline โ€” Lemhi County, ID

Melon Planting Calendar

Activity When Date Range
Start Indoors April 28 Apr 28 โ€“ May 12
Transplant Outdoors June 30 Jun 30 โ€“ Jul 14
Direct Sow June 23 Jun 23 โ€“ Jul 14
Harvest September 8 Sep 8 โ€“ Oct 27

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

97 days in Lemhi County

Growing Tips for Melon in Lemhi County

Direct sow Melon outdoors after June 09 in Lemhi County when soil has warmed and frost danger has passed.

Your 97.0-day growing season in Lemhi County is tight for Melon (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Lemhi County receives only 13" of rain annually. Melon needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 3-4 weeks before transplanting. Plant on raised mounds of compost-enriched soil. Reduce watering as fruits ripen to concentrate sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Cucumber

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Melon in Lemhi County, ID?

Lemhi County is in Zone 4b with an average last frost of June 9. Plan your Melon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lemhi County, ID?

Lemhi County, Idaho is in USDA Hardiness Zone 4b. The average last spring frost is June 9 and first fall frost is September 14.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Lemhi County, ID. Local conditions may vary. Last updated: April 2026.