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When to Plant Sweet Potatoes in Wicomico County, MD

Wicomico County, Maryland Zone 7b May

Your May gardening checklist

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 9
Avg. first frost November 1
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 14.1 hrs
  1. Time to start sweet potatoes inside

    You're about 25 weeks out from your last frost — the perfect window to get these germinating indoors.

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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.

Wicomico County, Maryland is in USDA Zone 7b. The average last spring frost is April 9 and the first fall frost is November 1, giving you a growing season of approximately 206 days.

At an elevation of 728 feet, Wicomico County receives approximately 48.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Sweet Potatoes during the growing season.

Wicomico County, MD (Zone 7b) Long season
206 days
Last Spring Frost April 9
206 growing days
First Fall Frost November 1

Wicomico County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (50 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jul 16 – Sep 3
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jul 23 – Sep 10
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 15 Transplant: May 17 🍅 Harvest: Aug 16 – Oct 4

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 Wicomico County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.3%). 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 35 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" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.9" 0" ✅ Rainfall sufficient
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 4.5" 0" ✅ Rainfall sufficient
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 4.3" 4" 0.3" 💧 Light watering
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Wicomico 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 ~1,995 GDD — county provides 3,914 GDD Excellent fit

Sweet Potatoes Planting Timeline — Wicomico County, MD

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 16 Apr 16 – May 7
Harvest July 23 Jul 23 – Sep 10

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

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 7b

📆 Growing Season

206 days in Wicomico County

Growing Tips for Sweet Potatoes in Wicomico County

Direct sow Sweet Potatoes outdoors after April 09 in Wicomico 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 Wicomico County, MD?

Wicomico County is in Zone 7b with an average last frost of April 9. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wicomico County, MD?

Wicomico County, Maryland is in USDA Hardiness Zone 7b. The average last spring frost is April 9 and first fall frost is November 1.

🌱

Your Wicomico County Garden Planner — Free

A 24-page printable planner built for Wicomico County (Zone 7b). 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 Wicomico County, MD. 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.