When to Plant Lentils in Petroleum County, MT
What to do in May
Your Petroleum County, Montana garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Move lentils into the garden
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
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Outdoor sowing time: lentils
These tolerate cool soil, so you're not gambling by sowing now.
Before June arrives, get these ready
- Starting indoors: lentils
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.
Petroleum County, Montana is in USDA Zone 4b. The average last spring frost is May 18 and the first fall frost is September 24, giving you a growing season of approximately 129 days.
At an elevation of 8,358 feet, Petroleum County receives approximately 13.7 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.
Petroleum County Soil Profile
Soil Type
Loam
Soil pH
6.8-8.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Petroleum County
How your county's soil matches Lentils's growing requirements.
Soil pH
Your soil pH (6.8–8.2) overlaps with Lentils's range (6.0–8.0), though not a perfect match.
Soil Texture
The loam soil in Petroleum County is excellent for Lentils — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Lentils.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Lentils.
How to Plant Lentils
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.2" | 0" | ❄️ Dormant |
| Apr | — | 1.3" | 0" | ❄️ Dormant |
| May | 2.6" | 1.8" | 0.8" | 💧 Light watering |
| Jun | 2.6" | 0.9" | 1.7" | 🚿 Regular watering |
| Jul | 2.6" | 1.2" | 1.4" | 🚿 Regular watering |
| Aug | 2.6" | 1.5" | 1.1" | 💧 Light watering |
| Sep | 2.6" | 1.2" | 1.4" | 🚿 Regular watering |
| Oct | — | 1.2" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Petroleum 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 Planting Timeline — Petroleum County, MT
Lentils Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 6 | Apr 6 – Apr 20 |
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Direct Sow | May 11 | May 11 – Jun 1 |
| Harvest | August 10 | Aug 10 – Sep 21 |
| Fall Sowing | July 2 | Jul 2 – Jul 16 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · 1-2 times/week
📅 Days to Maturity
80–110 days
🧪 Soil pH
Needs 6–8 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
129 days in Petroleum County
Growing Tips for Lentils in Petroleum County
Direct sow Lentils outdoors after May 18 in Petroleum 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
Check more plant combinations with our Companion Planting Checker →
Lentils in Other Locations
Frequently Asked Questions
When should I plant Lentils in Petroleum County, MT?
Petroleum County is in Zone 4b with an average last frost of May 18. Plan your Lentils planting based on this frost date — see the calendar above for exact timing.
What planting zone is Petroleum County, MT?
Petroleum County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 18 and first fall frost is September 24.
Your Petroleum County Garden Planner — Free
A 24-page printable planner built for Petroleum County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.