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When to Plant Lentils in Caribou County, ID

Caribou County, Idaho Zone 5a May

May in Caribou County, Idaho — your action list

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Caribou County, Idaho.

Avg. last frost May 30
Avg. first frost September 16
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
  1. Plant out lentils

    Frost risk is low now in Caribou County, Idaho. If you've been covering beds overnight, you can stop.

  2. Put lentils seeds straight in the ground

    Your soil is 34°F — warm enough for these to germinate without babying.

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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.

Caribou County, Idaho is in USDA Zone 5a. The average last spring frost is May 30 and the first fall frost is September 16, giving you a growing season of approximately 109 days.

At an elevation of 6,562 feet, Caribou County receives approximately 15.3 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Lentils to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Lentils successfully. Mulch heavily to conserve soil moisture.

Caribou County, ID (Zone 5a) Short season
109 days
Last Spring Frost May 30
109 growing days
First Fall Frost September 16
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Caribou County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 13 Transplant: May 18 🍅 Harvest: Aug 10 – Sep 21
Recommended (50%) ✗ May not fit
Start indoors: Apr 25 Transplant: May 30 🍅 Harvest: Aug 22 – Oct 3
Safe Start (90%) ✗ May not fit
Start indoors: May 13 Transplant: Jun 17 🍅 Harvest: Sep 9 – Oct 21

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 Caribou County

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

Soil pH

Your soil pH (6.8–8.1) overlaps with Lentils's range (6.0–8.0), though not a perfect match.

Soil Texture

The loam soil in Caribou County is excellent for Lentils — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Lentils.

How to Plant Lentils

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 12 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Lentils

Lentils needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Lentils Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 2.6" 1.6" 1" 💧 Light watering
Jun 2.6" 1" 1.6" 🚿 Regular watering
Jul 2.6" 1.5" 1.1" 💧 Light watering
Aug 2.6" 1.4" 1.2" 💧 Light watering
Sep 2.6" 1.2" 1.4" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Caribou County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Lentils 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.

Lentils needs ~1,021 GDD — county provides 1,171 GDD Good fit

Lentils Planting Timeline — Caribou County, ID

Lentils Planting Calendar

Activity When Date Range
Start Indoors April 25 Apr 25 – May 9
Transplant Outdoors May 30 May 30 – Jun 13
Direct Sow May 16 May 16 – Jun 6
Harvest August 22 Aug 22 – Oct 3
Fall Sowing July 8 Jul 8 – Jul 22

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Only during dry spells

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

109 days in Caribou County

Growing Tips for Lentils in Caribou County

Direct sow Lentils outdoors after May 30 in Caribou County when soil has warmed and frost danger has passed.

Your 109.0-day growing season in Caribou County is tight for Lentils (80.0-110.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Lentils in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lentils in Caribou County, ID?

Caribou County is in Zone 5a with an average last frost of May 30. Plan your Lentils planting based on this frost date — see the calendar above for exact timing.

What planting zone is Caribou County, ID?

Caribou County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 30 and first fall frost is September 16.

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Your Caribou County Garden Planner — Free

A 24-page printable planner built for Caribou County (Zone 5a). 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 Caribou County, ID. 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.