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When to Plant Sweet Potatoes in Franklin County, FL

Franklin County, Florida Zone 9a May

Your May game plan for Franklin County, Florida

Your garden in Franklin County, Florida is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost February 25
Avg. first frost November 28
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
Looking ahead to June
  • First harvests: 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.

Franklin County, Florida is in USDA Zone 9a. The average last spring frost is February 25 and the first fall frost is November 28, giving you a growing season of approximately 276 days.

At an elevation of 487 feet, Franklin County receives approximately 59.9 inches of rainfall annually with predominantly sand soil. Summer highs average 96°F, so Sweet Potatoes may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sweet Potatoes will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.

Franklin County, FL (Zone 9a) Year-round
276 days
Last Spring Frost February 25
276 growing days
First Fall Frost November 28
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Franklin County Soil Profile

Soil Type

Sand

Soil pH

4.9-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (139 days to spare)
Start indoors: Dec 28 Transplant: Feb 15 🍅 Harvest: May 17 – Jul 5
Recommended (50%) ✓ Fits season (129 days to spare)
Start indoors: Jan 14 Transplant: Mar 4 🍅 Harvest: Jun 3 – Jul 22
Safe Start (90%) ✓ Fits season (130 days to spare)
Start indoors: Feb 3 Transplant: Mar 24 🍅 Harvest: Jun 23 – Aug 11

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 Franklin County

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

Soil pH

Your soil pH (4.9–6.0) is more acidic than Sweet Potatoes prefers (5.5–6.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Franklin County warms quickly in spring but drains fast. Sweet Potatoes will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Sweet Potatoes.

Organic Matter

Organic matter is low (1.6%). Add 2-3 inches of compost before planting 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
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 966 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 2.6" 0" ❄️ Dormant
Feb 4.3" 2.8" 1.5" 💧 Light watering
Mar 4.3" 3.2" 1.1" 💧 Light watering
Apr 4.3" 2.6" 1.7" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 7.6" 0" ✅ Rainfall sufficient
Jul 4.3" 9.2" 0" ✅ Rainfall sufficient
Aug 4.3" 10" 0" ✅ Rainfall sufficient
Sep 4.3" 7.4" 0" ✅ Rainfall sufficient
Oct 4.3" 4.9" 0" ✅ Rainfall sufficient
Nov 4.3" 2.9" 1.4" 💧 Light watering
Dec 2.8" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Franklin 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 ~2,310 GDD — county provides 6,094 GDD Excellent fit

Sweet Potatoes Planting Timeline — Franklin County, FL

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 14 Jan 14 – Jan 28
Transplant Outdoors March 4 Mar 4 – Mar 18
Direct Sow February 25 Feb 25 – Mar 18
Harvest June 3 Jun 3 – Jul 22

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

276 days in Franklin County

Growing Tips for Sweet Potatoes in Franklin County

Direct sow Sweet Potatoes outdoors after February 25 in Franklin County when soil has warmed and frost danger has passed.

Sandy soil in Franklin County dries quickly — mulch Sweet Potatoes with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Franklin County, provide afternoon shade for Sweet Potatoes and water deeply in the morning.

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 Franklin County, FL?

Franklin County is in Zone 9a with an average last frost of February 25. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, FL?

Franklin County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 25 and first fall frost is November 28.

🌱

Your Franklin County Garden Planner — Free

A 24-page printable planner built for Franklin County (Zone 9a). 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 Franklin County, FL. 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.