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When to Plant Sweet Potatoes in Letcher County, KY

Letcher County, Kentucky Zone 7a May

What to do in May

Each item below is timed to Letcher County, Kentucky's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 13
Avg. first frost October 22
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14 hrs
June prep starts now
  • 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.

Letcher County, Kentucky is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 22, giving you a growing season of approximately 192 days.

At an elevation of 3,749 feet, Letcher County receives approximately 54.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Sweet Potatoes during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.

Letcher County, KY (Zone 7a) Moderate season
192 days
Last Spring Frost April 13
192 growing days
First Fall Frost October 22
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Letcher County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (38 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Jul 22 – Sep 9
Recommended (50%) ✓ Fits season (38 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jul 27 – Sep 14
Safe Start (90%) ✓ Fits season (33 days to spare)
Start indoors: Mar 12 Transplant: May 14 🍅 Harvest: Aug 13 – Oct 1

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 Letcher County

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

Soil pH

Your soil pH (5.5–6.5) is within Sweet Potatoes's preferred range (5.5–6.5).

Soil Texture

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

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
1.2″/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 4.5" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 5.4" 0" ❄️ Dormant
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 5.4" 0" ✅ Rainfall sufficient
Aug 4.3" 5.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.1" 0" ❄️ Dormant
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Letcher 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 ~1,522 GDD — county provides 2,784 GDD Excellent fit

Sweet Potatoes Planting Timeline — Letcher County, KY

Sweet 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 27 Jul 27 – 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
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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: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

192 days in Letcher County

Growing Tips for Sweet Potatoes in Letcher County

Direct sow Sweet Potatoes outdoors after April 13 in Letcher 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 Letcher County, KY?

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

What planting zone is Letcher County, KY?

Letcher County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 22.

🌱

Your Letcher County Garden Planner — Free

A 24-page printable planner built for Letcher 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 Letcher 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.