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When to Plant Potatoes in Butte County, ID

Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.

Butte County, Idaho is in USDA Zone 4b. The average last spring frost is June 1 and the first fall frost is September 14, giving you a growing season of approximately 105 days.

At an elevation of 7,254 feet, Butte County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Potatoes to ensure they mature before fall.

Butte County, ID (Zone 4b) Short season
105 days
Last Spring Frost June 1
105 growing days
First Fall Frost September 14

Butte County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 19 Transplant: Jun 11 🍅 Harvest: Aug 20 – Oct 29
Recommended (50%) ✗ May not fit
Start indoors: Mar 30 Transplant: Jun 22 🍅 Harvest: Aug 31 – Nov 9
Safe Start (90%) ✗ May not fit
Start indoors: Apr 15 Transplant: Jul 8 🍅 Harvest: Sep 16 – Nov 25

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 45 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Potatoes needs ~1,235 GDD — county provides 1,365 GDD Good fit

Potatoes Planting Timeline โ€” Butte County, ID

Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 โ€“ Apr 13
Transplant Outdoors June 22 Jun 22 โ€“ Jul 6
Direct Sow June 15 Jun 15 โ€“ Jul 6
Harvest August 31 Aug 31 โ€“ Nov 9

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

70โ€“120 days

Soil pH

5 โ€“ 6.5

USDA Zone

Zone 4b

Growing Season

105 days

Growing Tips for Butte County

Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

Level Up Your Garden

Frequently Asked Questions

When should I plant Potatoes in Butte County, ID?

Butte County is in Zone 4b with an average last frost of June 1. Plan your Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Butte County, ID?

Butte County, Idaho is in USDA Hardiness Zone 4b. The average last spring frost is June 1 and first fall frost is September 14.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Butte County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Butte County, ID. Local conditions may vary. Last updated: April 2026.