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When to Plant Lentils in Missoula County, MT

Missoula County, Montana Zone 5b May

Top priorities for Missoula County, Montana gardeners in May

May is a pivotal month for Missoula County, Montana gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 14
Avg. first frost September 23
Soil temp (4") 32°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Harden off and plant lentils

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

June will be here before you know it — start on
  • Starting indoors: lentils

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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.

Missoula County, Montana is in USDA Zone 5b. The average last spring frost is May 14 and the first fall frost is September 23, giving you a growing season of approximately 132 days.

At an elevation of 8,019 feet, Missoula County receives approximately 15.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Lentils during the growing season. With low rainfall, drip irrigation is essential for growing Lentils successfully. Mulch heavily to conserve soil moisture.

Missoula County, MT (Zone 5b) Short season
132 days
Last Spring Frost May 14
132 growing days
First Fall Frost September 23

Missoula County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jul 31 – Sep 11
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Aug 6 – Sep 17
Safe Start (90%) ✓ Fits season (5 days to spare)
Start indoors: Apr 30 Transplant: Jun 4 🍅 Harvest: Aug 27 – Oct 8

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 Missoula County

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

Soil pH

Your soil pH (6.2–7.7) is within Lentils's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 133 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" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 2.6" 1.7" 0.9" 💧 Light watering
Jun 2.6" 1.1" 1.5" 🚿 Regular watering
Jul 2.6" 1.3" 1.3" 🚿 Regular watering
Aug 2.6" 1.9" 0.7" 💧 Light watering
Sep 2.6" 1.4" 1.2" 💧 Light watering
Oct 1.5" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Missoula 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 ~1,449 GDD — county provides 2,013 GDD Excellent fit

Lentils Planting Timeline — Missoula County, MT

Lentils Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 14 May 14 – May 28
Direct Sow April 30 Apr 30 – May 21
Harvest August 6 Aug 6 – Sep 17
Fall Sowing July 15 Jul 15 – Jul 29

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

Month-by-Month Timeline

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

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: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

132 days in Missoula County

Growing Tips for Lentils in Missoula County

Direct sow Lentils outdoors after May 14 in Missoula County when soil has warmed and frost danger has passed.

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 Missoula County, MT?

Missoula County is in Zone 5b with an average last frost of May 14. Plan your Lentils planting based on this frost date — see the calendar above for exact timing.

What planting zone is Missoula County, MT?

Missoula County, Montana is in USDA Hardiness Zone 5b. The average last spring frost is May 14 and first fall frost is September 23.

🌱

Your Missoula County Garden Planner — Free

A 24-page printable planner built for Missoula County (Zone 5b). 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 Missoula County, MT. 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.