When to Plant Potatoes in Union County, NJ
Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.
Union County, New Jersey 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 814 feet, Union County receives approximately 49.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Potatoes during the growing season.
Union County Soil Profile
Soil Type
Silt Loam
Soil pH
4.8-6.5
Drainage
Well Drained
Plant Planting Risk Windows
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.
Plant Water Budget
Potatoes Planting Timeline — Union County, NJ
Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 8 | Feb 8 – Feb 22 |
| Transplant Outdoors | April 12 | Apr 12 – Apr 26 |
| Direct Sow | April 5 | Apr 5 – Apr 26 |
| Harvest | June 21 | Jun 21 – Aug 30 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
70–120 days
Soil pH
5 – 6.5
USDA Zone
Zone 7a
Growing Season
228 days
Growing Tips for Union County
Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Potatoes in Other Locations
Frequently Asked Questions
When should I plant Potatoes in Union County, NJ?
Union County is in Zone 7a with an average last frost of March 29. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union County, NJ?
Union County, New Jersey is in USDA Hardiness Zone 7a. The average last spring frost is March 29 and first fall frost is November 12.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Union 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.