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When to Plant Cilantro in Union County, NJ

Cilantro is a dual-purpose herb providing fresh leaves (cilantro) and dried seeds (coriander). It bolts quickly in heat, producing flowers beloved by beneficial insects.

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 Cilantro 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 (130 days to spare)
Start indoors: Feb 18 Transplant: Mar 18 🍅 Harvest: Apr 29 – Jul 1
Recommended (50%) ✓ Fits season (130 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: May 3 – Jul 5
Safe Start (90%) ✓ Fits season (139 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: May 14 – Jul 16

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
Cilantro needs ~988 GDD — county provides 4,503 GDD Excellent fit

Cilantro Planting Timeline โ€” Union County, NJ

Cilantro Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 โ€“ Mar 8
Transplant Outdoors March 22 Mar 22 โ€“ Apr 5
Direct Sow March 15 Mar 15 โ€“ Apr 5
Fall Sowing September 3 Sep 3 โ€“ Sep 17
Harvest May 3 May 3 โ€“ Jul 5

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

228 days

Growing Tips for Union County

Succession sow every 2-3 weeks. Provide afternoon shade in warm weather. Harvest leaves before flowering or allow some plants to go to seed for coriander and self-sowing.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Level Up Your Garden

Frequently Asked Questions

When should I plant Cilantro in Union County, NJ?

Union County is in Zone 7a with an average last frost of March 29. Plan your Cilantro 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.

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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.

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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.