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When to Plant Potatoes in Mitchell, OR

Potatoes
Wheeler County, Oregon Zone 7a July

This month in Wheeler County, Oregon

We've pulled the most time-sensitive tasks for Wheeler County, Oregon this July and put them front and centre. Tackle them in order.

Avg. last frost May 23
Avg. first frost September 23
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 15.1 hrs
  1. Time to start potatoes inside

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

August prep starts now
  • First harvests: potatoes

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

Mitchell, Oregon is in USDA Zone 7a. The average last spring frost is May 23 and the first fall frost is September 23, giving you a growing season of approximately 123 days.

At an elevation of 2,175 feet, Wheeler County receives approximately 22.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Potatoes to ensure they mature before fall.

Mitchell, OR (Zone 7a) Short season
123 days
Last Spring Frost May 23
123 growing days
First Fall Frost September 23

Mitchell Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Potatoes Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 28 Transplant: May 30 🍅 Harvest: Aug 8 – Oct 17
Recommended (50%) ✗ May not fit
Start indoors: Apr 4 Transplant: Jun 6 🍅 Harvest: Aug 15 – Oct 24
Safe Start (90%) ✗ May not fit
Start indoors: May 1 Transplant: Jul 3 🍅 Harvest: Sep 11 – Nov 20

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 Mitchell

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

Soil pH

Your soil pH (5.2–6.3) is within Potatoes's preferred range (5.0–6.5).

Soil Texture

The silt loam soil in Wheeler County is excellent for Potatoes — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) — Potatoes will thrive.

How to Plant Potatoes

1"
Planting Depth
15"
Between Plants
24"
Between Rows

How Much Potatoes to Grow

3-5 lbs
Average yield per plant
5
Plants per person
12.5 sq ft
Space per person

For a family of 4, plant approximately 20 potatoes plants in about 50 sq ft. In Wheeler County's 123-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Potatoes Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 242 gal / 100 sq ft

Monthly Watering Guide for Potatoes

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

Month Potatoes Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 0.4" 3.9" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.8" 3.5" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 3.3" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

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

Potatoes 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.

Potatoes needs ~1,164 GDD — county provides 1,506 GDD Good fit

Potatoes Planting Timeline — Mitchell, OR

Potatoes Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors June 6 Jun 6 – Jun 20
Direct Sow May 30 May 30 – Jun 20
Harvest August 15 Aug 15 – Oct 24

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 5–6.5 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

123 days in Wheeler County

Growing Tips for Potatoes in Mitchell

Direct sow Potatoes outdoors after May 23 in Wheeler County when soil has warmed and frost danger has passed.

Your 123.0-day growing season in Wheeler County is tight for Potatoes (70.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Potatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

Wheeler County receives only 23" of rain annually. Potatoes needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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.

Recommended Potatoes Varieties for Mitchell

Early-maturing potatoes for your season

Yukon Gold (65d) Red Norland (70d) Irish Cobbler (70d)

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

🌱

Your Wheeler County Garden Planner — Free

A 22-page printable planner built for Wheeler County (Zone 7a). 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 Wheeler County, OR. Local conditions may vary. Last updated: July 2026.