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When to Plant Tomatoes in Warren County, NJ

Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Warren County, New Jersey is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 27, giving you a growing season of approximately 194 days.

At an elevation of 369 feet, Warren County receives approximately 48.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Tomatoes during the growing season.

Warren County, NJ (Zone 6a) Moderate season
194 days
Last Spring Frost April 16
194 growing days
First Fall Frost October 27

Warren 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 (47 days to spare)
Start indoors: Feb 9 Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 31
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Feb 19 Transplant: Apr 30 🍅 Harvest: Jul 2 – Sep 10
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Mar 14 Transplant: May 23 🍅 Harvest: Jul 25 – Oct 3

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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Tomatoes needs ~1,051 GDD — county provides 2,813 GDD Excellent fit

Tomatoes Planting Timeline โ€” Warren County, NJ

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 โ€“ Mar 5
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Direct Sow April 23 Apr 23 โ€“ May 14
Harvest July 2 Jul 2 โ€“ Sep 10

Plant 0.5" deep ยท 24" apart ยท Rows 36" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Harvest
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

60โ€“85 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6a

Growing Season

194 days

Growing Tips for Warren County

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Level Up Your Garden

๐ŸŒพ Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35ยฐF, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Warren County, NJ?

Warren County is in Zone 6a with an average last frost of April 16. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Warren County, NJ?

Warren County, New Jersey is in USDA Hardiness Zone 6a. The average last spring frost is April 16 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Warren County gardeners in Zone 6a 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 Warren County, NJ. Local conditions may vary. Last updated: April 2026.