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When to Plant Sweet Potatoes in Clay County, FL

Clay County, Florida Zone 9a May

Clay County, Florida gardeners: here's your May plan

Your Clay County, Florida garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost February 18
Avg. first frost November 27
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Start harvesting sweet potatoes

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

June prep starts now
  • 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.

Clay County, Florida is in USDA Zone 9a. The average last spring frost is February 18 and the first fall frost is November 27, giving you a growing season of approximately 282 days.

At an elevation of 122 feet, Clay County receives approximately 54.3 inches of rainfall annually with predominantly sand soil. Summer highs average 99°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.

Clay County, FL (Zone 9a) Year-round
282 days
Last Spring Frost February 18
282 growing days
First Fall Frost November 27
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Clay County Soil Profile

Soil Type

Sand

Soil pH

5-5.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (134 days to spare)
Start indoors: Dec 29 Transplant: Feb 16 🍅 Harvest: May 18 – Jul 6
Recommended (50%) ✓ Fits season (135 days to spare)
Start indoors: Jan 7 Transplant: Feb 25 🍅 Harvest: May 27 – Jul 15
Safe Start (90%) ✓ Fits season (126 days to spare)
Start indoors: Feb 8 Transplant: Mar 29 🍅 Harvest: Jun 28 – Aug 16

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 Clay County

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

Soil pH

Your soil pH (5.0–5.8) is more acidic than Sweet Potatoes prefers (5.5–6.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Clay 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
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,245 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" 3" 1.3" 💧 Light watering
Mar 4.3" 3.1" 1.2" 💧 Light watering
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 8.5" 0" ✅ Rainfall sufficient
Jul 4.3" 7.4" 0" ✅ Rainfall sufficient
Aug 4.3" 7.4" 0" ✅ Rainfall sufficient
Sep 4.3" 6.6" 0" ✅ Rainfall sufficient
Oct 4.3" 5.1" 0" ✅ Rainfall sufficient
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Clay 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 ~2,546 GDD — county provides 6,862 GDD Excellent fit

Sweet Potatoes Planting Timeline — Clay County, FL

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 – Jan 21
Transplant Outdoors February 25 Feb 25 – Mar 11
Direct Sow February 18 Feb 18 – Mar 11
Harvest May 27 May 27 – Jul 15

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April
May Harvest
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

282 days in Clay County

Growing Tips for Sweet Potatoes in Clay County

Direct sow Sweet Potatoes outdoors after February 18 in Clay County when soil has warmed and frost danger has passed.

Sandy soil in Clay 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 99°F in Clay 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 Clay County, FL?

Clay County is in Zone 9a with an average last frost of February 18. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clay County, FL?

Clay County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 18 and first fall frost is November 27.

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Your Clay County Garden Planner — Free

A 24-page printable planner built for Clay 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 Clay 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.