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When to Plant Sweet Potatoes in Adair County, KY

Adair County, Kentucky Zone 7a May

Top priorities for Adair County, Kentucky gardeners in May

Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 17
Avg. first frost October 21
Soil temp (4") 57°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
  1. Time to transplant sweet potatoes

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

Before June arrives, get these ready
  • Starting indoors: sweet potatoes

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Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.

Adair County, Kentucky is in USDA Zone 7a. The average last spring frost is April 17 and the first fall frost is October 21, giving you a growing season of approximately 187 days.

At an elevation of 2,442 feet, Adair County receives approximately 42.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Sweet Potatoes during the growing season.

Adair County, KY (Zone 7a) Moderate season
187 days
Last Spring Frost April 17
187 growing days
First Fall Frost October 21

Adair County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Feb 20 Transplant: Apr 24 🍅 Harvest: Jul 24 – Sep 11
Recommended (50%) ✓ Fits season (33 days to spare)
Start indoors: Feb 27 Transplant: May 1 🍅 Harvest: Jul 31 – Sep 18
Safe Start (90%) ✓ Fits season (27 days to spare)
Start indoors: Mar 16 Transplant: May 18 🍅 Harvest: Aug 17 – Oct 5

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 Adair County

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

Soil pH

Your soil pH (5.7–7.1) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Sweet Potatoes.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Sweet Potatoes.

How to Plant Sweet Potatoes

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sweet Potatoes

Sweet 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 Sweet Potatoes Needs Rainfall You Supplement Action
Jan 4.1" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 3.3" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

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

Sweet 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.

Sweet Potatoes needs ~1,759 GDD — county provides 3,132 GDD Excellent fit

Sweet Potatoes Planting Timeline — Adair County, KY

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Harvest July 31 Jul 31 – Sep 18

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April 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 · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

187 days in Adair County

Growing Tips for Sweet Potatoes in Adair County

Direct sow Sweet Potatoes outdoors after April 17 in Adair County when soil has warmed and frost danger has passed.

General growing tips

Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Potatoes in Adair County, KY?

Adair County is in Zone 7a with an average last frost of April 17. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adair County, KY?

Adair County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 17 and first fall frost is October 21.

🌱

Your Adair County Garden Planner — Free

A 24-page printable planner built for Adair 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 Adair County, KY. 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.