Blog

When to Plant Sunchoke in Middlesex County, NJ

Sunchokes (Jerusalem artichokes) are a native sunflower relative grown for their knobby, nutty-flavored tubers. They are extremely productive and nearly impossible to eradicate.

Middlesex 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 947 feet, Middlesex County receives approximately 45.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94ยฐF, providing good warmth for Sunchoke during the growing season.

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

Middlesex County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Transplant: Apr 8 🍅 Harvest: Jul 29 – Sep 23
Recommended (50%) ✓ Fits season (46 days to spare)
Transplant: Apr 12 🍅 Harvest: Aug 2 – Sep 27
Safe Start (90%) ✓ Fits season (55 days to spare)
Transplant: Apr 23 🍅 Harvest: Aug 13 – Oct 8

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

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 328 gal / 100 sq ft
Sunchoke needs ~2,665 GDD — county provides 4,674 GDD Excellent fit

Sunchoke Planting Timeline โ€” Middlesex County, NJ

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors April 12 Apr 12 โ€“ Apr 26
Harvest August 2 Aug 2 โ€“ Sep 27

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

110โ€“150 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 7a

Growing Season

228 days

Growing Tips for Middlesex County

Plant tubers 4 inches deep in early spring. Contain plants with barriers as they spread aggressively. Harvest after frost or leave in ground and dig as needed through winter.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunchoke in Middlesex County, NJ?

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

What planting zone is Middlesex County, NJ?

Middlesex County, New Jersey 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 Middlesex 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 Middlesex County, NJ. Local conditions may vary. Last updated: April 2026.