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When to Plant Sweet Potatoes in Knott County, KY

Knott County, Kentucky Zone 7a May

Knott County, Kentucky gardeners: here's your May plan

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

Avg. last frost April 23
Avg. first frost October 18
Soil temp (4") 61°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
  1. Time to transplant sweet potatoes

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

Coming up in June — start thinking about
  • 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.

Knott County, Kentucky is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 18, giving you a growing season of approximately 178 days.

At an elevation of 2,201 feet, Knott County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Sweet Potatoes during the growing season.

Knott County, KY (Zone 7a) Moderate season
178 days
Last Spring Frost April 23
178 growing days
First Fall Frost October 18
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Knott County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 29 – Sep 16
Recommended (50%) ✓ Fits season (24 days to spare)
Start indoors: Mar 5 Transplant: May 7 🍅 Harvest: Aug 6 – Sep 24
Safe Start (90%) ✓ Fits season (18 days to spare)
Start indoors: Mar 24 Transplant: May 26 🍅 Harvest: Aug 25 – Oct 13

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 Knott County

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 59 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 3.2" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 3.1" 1.2" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Knott 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 2,581 GDD Excellent fit

Sweet Potatoes Planting Timeline — Knott County, KY

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Harvest August 6 Aug 6 – Sep 24

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

178 days in Knott County

Growing Tips for Sweet Potatoes in Knott County

Direct sow Sweet Potatoes outdoors after April 23 in Knott 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 Knott County, KY?

Knott County is in Zone 7a with an average last frost of April 23. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Knott County, KY?

Knott County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 18.

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Your Knott County Garden Planner — Free

A 24-page printable planner built for Knott 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 Knott 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.