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When to Plant Snow Peas in Caribou County, ID

Caribou County, Idaho Zone 5a May

May to-do list for Caribou County, Idaho

Your garden in Caribou County, Idaho is working on a schedule, even when you're not. Here's where you should be this May.

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 snow peas

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

  2. Seed snow peas outdoors

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

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Snow peas are a flat-podded pea variety eaten whole when the seeds inside are still tiny. They are essential in Asian stir-fries and have a delicate, sweet flavor.

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 Snow Peas to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Snow Peas 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) ✓ Fits season (1 days to spare)
Start indoors: Apr 13 Transplant: May 18 🍅 Harvest: Jul 13 – Sep 7
Recommended (50%) ✗ May not fit
Start indoors: Apr 25 Transplant: May 30 🍅 Harvest: Jul 25 – Sep 19
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: May 13 Transplant: Jun 17 🍅 Harvest: Aug 12 – Oct 7

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 Snow Peas's growing requirements.

Soil pH

Your soil pH (6.8–8.1) overlaps with Snow Peas's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Snow Peas

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

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

Succession Planting Snow Peas

2
successive plantings in your 109-day season

Sow every 5.7 weeks. Last sowing by Jul 13 to harvest before frost.

For a dedicated fall crop, sow by Jul 08.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 478 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Snow Peas

Snow Peas needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Snow Peas 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 4.3" 1.6" 2.7" 🚿 Regular watering
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.4" 2.9" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 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.

Snow 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.

Snow Peas needs ~618 GDD — county provides 1,171 GDD Excellent fit

Snow Peas Planting Timeline — Caribou County, ID

Snow Peas 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 July 25 Jul 25 – Sep 19
Fall Sowing July 8 Jul 8 – Jul 22

Plant 1" deep · 4" apart · Rows 18" 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 Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

109 days in Caribou County

Growing Tips for Snow Peas in Caribou County

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

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

Caribou County receives only 15" of rain annually. Snow Peas needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow in early spring. Pick pods frequently when they are flat and tender for best flavor. Provide support for climbing varieties.

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 Snow Peas in Caribou County, ID?

Caribou County is in Zone 5a with an average last frost of May 30. Plan your Snow Peas 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.

🌱

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.