Blog

When to Plant Lentils in Custer County, ID

Lentils are an ancient pulse crop producing small, lens-shaped seeds packed with protein and iron. They grow on short, bushy plants and are surprisingly easy to cultivate.

Custer County, Idaho is in USDA Zone 4a. The average last spring frost is June 18 and the first fall frost is September 5, giving you a growing season of approximately 79 days.

At an elevation of 5,189 feet, Custer County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Lentils to ensure they mature before fall.

Custer County, ID (Zone 4a) Very short season
79 days
Last Spring Frost June 18
79 growing days
First Fall Frost September 5

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.3-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 30 Transplant: Jun 11 🍅 Harvest: Sep 3 – Oct 15
Recommended (50%) ✗ May not fit
Start indoors: May 7 Transplant: Jun 18 🍅 Harvest: Sep 10 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: May 18 Transplant: Jun 29 🍅 Harvest: Sep 21 – Nov 2

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.

Plant Water Budget

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

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

Lentils needs ~950 GDD — county provides 790 GDD May not mature

Lentils Planting Timeline โ€” Custer County, ID

Lentils Planting Calendar

Activity When Date Range
Start Indoors May 7 May 7 โ€“ May 21
Transplant Outdoors June 18 Jun 18 โ€“ Jul 2
Direct Sow June 11 Jun 11 โ€“ Jul 2
Fall Sowing June 13 Jun 13 โ€“ Jun 27
Harvest September 10 Sep 10 โ€“ Oct 22

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

80โ€“110 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 4a

Growing Season

79 days

Growing Tips for Custer County

Direct sow in early spring as lentils tolerate frost. Provide short supports as plants tend to lodge. Harvest when lower pods turn brown. Pull entire plants and dry in bundles.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Level Up Your Garden

Frequently Asked Questions

When should I plant Lentils in Custer County, ID?

Custer County is in Zone 4a with an average last frost of June 18. Plan your Lentils planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Custer County, ID?

Custer County, Idaho is in USDA Hardiness Zone 4a. The average last spring frost is June 18 and first fall frost is September 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Custer County gardeners in Zone 4a 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 Custer County, ID. Local conditions may vary. Last updated: April 2026.