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When to Plant Sweet Potatoes in Madison County, FL

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.

Madison County, Florida is in USDA Zone 8b. The average last spring frost is March 5 and the first fall frost is November 25, giving you a growing season of approximately 265 days.

At an elevation of 434 feet, Madison County receives approximately 61.2 inches of rainfall annually with predominantly sand soil. Summer highs average 95ยฐF, so Sweet Potatoes may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Madison County, FL (Zone 8b) Long season
265 days
Last Spring Frost March 5
265 growing days
First Fall Frost November 25

Madison County Soil Profile

Soil Type

Sand

Soil pH

5.2-5.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (110 days to spare)
Start indoors: Jan 6 Transplant: Mar 10 🍅 Harvest: Jun 9 – Jul 28
Recommended (50%) ✓ Fits season (111 days to spare)
Start indoors: Jan 15 Transplant: Mar 19 🍅 Harvest: Jun 18 – Aug 6
Safe Start (90%) ✓ Fits season (114 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jul 8 – Aug 26

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 Madison County

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

Soil pH

Your soil pH (5.2โ€“5.7) is more acidic than Sweet Potatoes prefers (5.5โ€“6.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Madison 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 (1.4%). 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
1.0″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 934 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 3.2" 0" โ„๏ธ Dormant
Feb โ€” 3.6" 0" โ„๏ธ Dormant
Mar 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Apr 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
May 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jun 4.3" 7.7" 0" โœ… Rainfall sufficient
Jul 4.3" 8" 0" โœ… Rainfall sufficient
Aug 4.3" 9.6" 0" โœ… Rainfall sufficient
Sep 4.3" 8.6" 0" โœ… Rainfall sufficient
Oct 4.3" 4.6" 0" โœ… Rainfall sufficient
Nov 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Dec โ€” 2.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Madison County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~2,231 GDD — county provides 5,631 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Madison County, FL

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 15 Jan 15 โ€“ Jan 29
Transplant Outdoors March 19 Mar 19 โ€“ Apr 2
Direct Sow March 12 Mar 12 โ€“ Apr 2
Harvest June 18 Jun 18 โ€“ Aug 6

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 5.5โ€“6.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

265 days in Madison County

Growing Tips for Sweet Potatoes in Madison County

Direct sow Sweet Potatoes outdoors after March 05 in Madison County when soil has warmed and frost danger has passed.

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

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 Madison County, FL?

Madison County is in Zone 8b with an average last frost of March 5. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Madison County, FL?

Madison County, Florida is in USDA Hardiness Zone 8b. The average last spring frost is March 5 and first fall frost is November 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Madison County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

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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 Madison County, FL. Local conditions may vary. Last updated: April 2026.