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When to Plant Basil in Union County, NJ

Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.

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 93ยฐF, providing good warmth for Basil during the growing season.

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

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (95 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jun 3 – Aug 5
Recommended (50%) ✓ Fits season (95 days to spare)
Start indoors: Feb 8 Transplant: Apr 12 🍅 Harvest: Jun 7 – Aug 9
Safe Start (90%) ✓ Fits season (104 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 20

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
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Basil needs ~1,234 GDD — county provides 4,503 GDD Excellent fit

Basil Planting Timeline โ€” Union County, NJ

Basil 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 June 7 Jun 7 โ€“ Aug 9

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

50โ€“75 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

228 days

Growing Tips for Union County

Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Level Up Your Garden

๐ŸŒพ Save Your Own Basil Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower spikes dry brown on the plant.
Storage Store airtight; viable 5 years at 35ยฐF, under 45% humidity.

Isolate 150 ft between varieties. Different basil species can cross.

Frequently Asked Questions

When should I plant Basil in Union County, NJ?

Union County is in Zone 7a with an average last frost of March 29. Plan your Basil planting based on this frost date โ€” 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.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” 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.

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