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When to Plant Peas in Valley County, MT

Valley County, Montana Zone 4a May

May in the garden — Valley County, Montana

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 13
Avg. first frost September 21
Soil temp (4") 25°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Set out peas seedlings

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Outdoor sowing time: peas

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

A few tasks this May that'll pay off in June
  • Starting indoors: peas
  • Fall sowing: 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.

Valley County, Montana is in USDA Zone 4a. The average last spring frost is May 13 and the first fall frost is September 21, giving you a growing season of approximately 131 days.

At an elevation of 8,293 feet, Valley County receives approximately 23.2 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Peas to ensure they mature before fall.

Valley County, MT (Zone 4a) Short season
131 days
Last Spring Frost May 13
131 growing days
First Fall Frost September 21

Valley County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (14 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Jul 5 – Aug 30
Recommended (50%) ✓ Fits season (19 days to spare)
Start indoors: Apr 1 Transplant: May 13 🍅 Harvest: Jul 8 – Sep 2
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Apr 23 Transplant: Jun 4 🍅 Harvest: Jul 30 – Sep 24

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 Valley County

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

Soil pH

Your soil pH (6.6–8.2) overlaps with Peas's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). 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 131-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.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 3" 2.7" 0.3" 💧 Light watering
Jun 3" 1.8" 1.2" 💧 Light watering
Jul 3" 1.9" 1.1" 💧 Light watering
Aug 3" 2.6" 0.4" 💧 Light watering
Sep 3" 2.1" 0.9" 💧 Light watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.7" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Valley 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 ~625 GDD — county provides 1,310 GDD Excellent fit

Peas Planting Timeline — Valley County, MT

Peas Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors May 13 May 13 – May 27
Direct Sow May 6 May 6 – May 27
Harvest July 8 Jul 8 – Sep 2
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 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 · Natural rainfall sufficient

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

131 days in Valley County

Growing Tips for Peas in Valley County

Direct sow Peas outdoors after May 13 in Valley 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 Valley County, MT?

Valley County is in Zone 4a with an average last frost of May 13. Plan your Peas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Valley County, MT?

Valley County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 13 and first fall frost is September 21.

🌱

Your Valley County Garden Planner — Free

A 24-page printable planner built for Valley County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Valley 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.