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When to plant Peas in Cascade County, MT

In Zone 4b (Cascade County), direct-sow Peas between May 12 and June 2 for spring, after the May 19 last-frost mark. A second sowing from June 29 to July 13 extends the harvest into fall.

When to Plant Peas in Cascade County, MT

Peas
Cascade County, Montana Zone 4b July

Top priorities for Cascade County, Montana gardeners in July

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

Avg. last frost May 19
Avg. first frost September 21
Soil temp (4") 54°F
Watering High
Pest pressure High
Daylight 15.4 hrs
  1. It's harvest week for peas

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Coming up in August — start thinking about
  • First harvests: peas

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Peas are a cool-season legume that fixes nitrogen in the soil. Garden peas are shelled, while snap and snow peas are eaten pod and all.

Cascade County, Montana is in USDA Zone 4b. The average last spring frost is May 19 and the first fall frost is September 21, giving you a growing season of approximately 125 days.

At an elevation of 6,585 feet, Cascade County receives approximately 21.8 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Peas to ensure they mature before fall.

Cascade County, MT (Zone 4b) Short season
125 days
Last Spring Frost May 19
125 growing days
First Fall Frost September 21

Cascade County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.2

Drainage

Well Drained

Peas Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 1
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Apr 7 Transplant: May 19 🍅 Harvest: Jul 14 – Sep 8
Safe Start (90%) ✓ Fits season (3 days to spare)
Start indoors: May 1 Transplant: Jun 12 🍅 Harvest: Aug 7 – Oct 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.

Soil Compatibility in Cascade County

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

Soil pH

Your soil pH (6.8–8.2) overlaps with Peas's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Peas.

Organic Matter

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

How to Plant Peas

1"
Planting Depth
4"
Between Plants
18"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Peas

2
successive plantings in your 125-day season

Sow every 6.3 weeks. Last sowing by Jul 13 to harvest before frost.

For a dedicated fall crop, sow by Jun 29.

Peas Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 237 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Peas

Peas needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Peas Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 3" 2.3" 0.7" 💧 Light watering
Jun 3" 1.5" 1.5" 🚿 Regular watering
Jul 3" 2.1" 0.9" 💧 Light watering
Aug 3" 2" 1" 💧 Light watering
Sep 3" 1.8" 1.2" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

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

Peas 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.

Peas needs ~766 GDD — county provides 1,531 GDD Excellent fit

Peas Planting Timeline — Cascade County, MT

Peas Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 12 May 12 – Jun 2
Harvest July 14 Jul 14 – Sep 8
Fall Sowing June 29 Jun 29 – Jul 13

Plant 1" deep · 4" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

125 days in Cascade County

Growing Tips for Peas in Cascade County

Direct sow Peas outdoors after May 19 in Cascade County when soil has warmed and frost danger has passed.

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

General growing tips

Direct sow as early as soil can be worked in spring. Inoculate seeds with rhizobium for best nitrogen fixation. Provide trellising for climbing varieties.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Peas Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let pods dry brown and papery on the vine.
Storage Store airtight; viable 3 years at 35°F, under 45% humidity.

Very easy to save. Self-pollinating means varieties stay true.

Frequently Asked Questions

When should I plant Peas in Cascade County, MT?

Cascade County is in Zone 4b with an average last frost of May 19. Plan your Peas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cascade County, MT?

Cascade County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 19 and first fall frost is September 21.

When should I plant Peas in Cascade County, MT?

In Cascade County, MT, plant Peas after the last frost (around May 19) and before the first frost (around September 21). Best results when soil holds above 50°F.

What growing zone is Cascade County, MT for Peas?

Cascade County sits in USDA Zone 4b. Peas grows reliably in zones 2a through 11b, so it's a good fit here.

Can Peas grow in Cascade County's climate?

Yes — Peas grows well in Cascade County's temperate climate. Cascade County averages a 125-day frost-free season, with last frost around May 19 and first frost around September 21.

🌱

Your Cascade County Garden Planner — Free

A 22-page printable planner built for Cascade 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.

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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 Cascade County, MT. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.