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When to Plant Potatoes in Dewey County, OK

Dewey County, Oklahoma Zone 7a May

May in the garden — Dewey County, Oklahoma

We've pulled the most time-sensitive tasks for Dewey County, Oklahoma this May and put them front and centre. Tackle them in order.

Avg. last frost April 13
Avg. first frost October 24
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
Looking ahead to June
  • Starting indoors: 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.

Dewey County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.

At an elevation of 745 feet, Dewey County receives approximately 28.5 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Potatoes during the growing season.

Dewey County, OK (Zone 7a) Moderate season
194 days
Last Spring Frost April 13
194 growing days
First Fall Frost October 24

Dewey County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Jun 29 – Sep 7
Recommended (50%) ✓ Fits season (40 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jul 6 – Sep 14
Safe Start (90%) ✓ Fits season (40 days to spare)
Start indoors: Mar 11 Transplant: May 13 🍅 Harvest: Jul 22 – Sep 30

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 Dewey County

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

Soil pH

Your soil pH (6.2–7.2) is more alkaline than Potatoes prefers (5.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Potatoes will thrive.

How to Plant Potatoes

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

Succession Planting Potatoes

3
successive plantings in your 194-day season

Sow every 8 weeks. Last sowing by Jun 26 to harvest before frost.

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 794 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.7" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 3.5" 0.8" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Dewey 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 ~1,876 GDD — county provides 3,831 GDD Excellent fit

Potatoes Planting Timeline — Dewey County, OK

Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 20 Apr 20 – May 11
Harvest July 6 Jul 6 – Sep 14

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

Month-by-Month Timeline

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

194 days in Dewey County

Growing Tips for Potatoes in Dewey County

Direct sow Potatoes outdoors after April 13 in Dewey County when soil has warmed and frost danger has passed.

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

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.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Potatoes in Dewey County, OK?

Dewey County is in Zone 7a with an average last frost of April 13. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dewey County, OK?

Dewey County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 24.

🌱

Your Dewey County Garden Planner — Free

A 24-page printable planner built for Dewey 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 Dewey County, OK. 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.