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When to Plant Sweet Potatoes in Bronx County, NY

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.

Bronx County, New York is in USDA Zone 7a. The average last spring frost is March 29 and the first fall frost is November 12, giving you a growing season of approximately 228 days.

At an elevation of 53 feet, Bronx County receives approximately 44.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Sweet Potatoes during the growing season.

Bronx County, NY (Zone 7a) Long season
228 days
Last Spring Frost March 29
228 growing days
First Fall Frost November 12

Bronx County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (74 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jul 8 – Aug 26
Recommended (50%) ✓ Fits season (74 days to spare)
Start indoors: Feb 8 Transplant: Apr 12 🍅 Harvest: Jul 12 – Aug 30
Safe Start (90%) ✓ Fits season (83 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jul 23 – Sep 10

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 Bronx County

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

Soil pH

Your soil pH (5.2โ€“6.4) overlaps with Sweet Potatoes's range (5.5โ€“6.5), though not a perfect match.

Soil Texture

The silt loam soil in Bronx County is excellent for Sweet Potatoes โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). 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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 373 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 โ€” 3.7" 0" โ„๏ธ Dormant
Feb โ€” 3.1" 0" โ„๏ธ Dormant
Mar 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Apr 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
May 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jun 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Jul 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Aug 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Sep 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Oct 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Nov 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Dec โ€” 3.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Bronx 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 ~1,680 GDD — county provides 3,648 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Bronx County, NY

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 8 Feb 8 โ€“ Feb 22
Transplant Outdoors April 12 Apr 12 โ€“ Apr 26
Direct Sow April 5 Apr 5 โ€“ Apr 26
Harvest July 12 Jul 12 โ€“ Aug 30

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March โ€”
April Transplant Outdoors Direct Sow
May โ€”
June โ€”
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 Only during dry spells

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 5.5โ€“6.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

228 days in Bronx County

Growing Tips for Sweet Potatoes in Bronx County

Direct sow Sweet Potatoes outdoors after March 29 in Bronx 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 Bronx County, NY?

Bronx County is in Zone 7a with an average last frost of March 29. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bronx County, NY?

Bronx County, New York is in USDA Hardiness Zone 7a. The average last spring frost is March 29 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bronx County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Bronx County, NY. Local conditions may vary. Last updated: April 2026.