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When to Plant Potatoes in Roy, UT

Potatoes
Weber County, Utah Zone 7a July

Your July gardening checklist

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

Avg. last frost May 26
Avg. first frost September 21
Soil temp (4") 62°F
Watering High
Pest pressure High
Daylight 14.7 hrs
  1. Indoor seed-starting week for potatoes

    Label every cell. You will absolutely forget which is which otherwise.

Before August arrives, get these ready
  • 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.

Roy, Utah is in USDA Zone 7a. The average last spring frost is May 26 and the first fall frost is September 21, giving you a growing season of approximately 118 days.

At an elevation of 6,211 feet, Weber County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Potatoes during the growing season. With low rainfall, drip irrigation is essential for growing Potatoes successfully. Mulch heavily to conserve soil moisture.

Roy, UT (Zone 7a) Short season
118 days
Last Spring Frost May 26
118 growing days
First Fall Frost September 21

Roy Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Potatoes Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 19 Transplant: May 21 🍅 Harvest: Jul 30 – Oct 8
Recommended (50%) ✗ May not fit
Start indoors: Apr 7 Transplant: Jun 9 🍅 Harvest: Aug 18 – Oct 27
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 Roy

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

Soil pH

Your soil pH (6.6–7.7) is more alkaline than Potatoes prefers (5.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Potatoes.

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 Weber County's 118-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
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 435 gal / 100 sq ft
Drought risk

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

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 1.3" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 2.1" 2.2" 🚿 Regular watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Weber 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 ~1,378 GDD — county provides 1,711 GDD Good fit

Potatoes Planting Timeline — Roy, UT

Potatoes Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors June 9 Jun 9 – Jun 23
Direct Sow June 2 Jun 2 – Jun 23
Harvest August 18 Aug 18 – Oct 27

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May
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 · 1-2 times/week

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

118 days in Weber County

Growing Tips for Potatoes in Roy

Direct sow Potatoes outdoors after May 26 in Weber County when soil has warmed and frost danger has passed.

Your 118.0-day growing season in Weber 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.

Weber County receives only 18" 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 Roy

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 Weber County Garden Planner — Free

A 22-page printable planner built for Weber 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 Weber County, UT. Local conditions may vary. Last updated: July 2026.