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When to Plant Zucchini in Sussex County, NJ

Sussex County, New Jersey Zone 6b May

Your May gardening checklist

We've pulled the most time-sensitive tasks for Sussex County, New Jersey this May and put them front and centre. Tackle them in order.

Avg. last frost March 29
Avg. first frost November 12
Soil temp (4") 61°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Begin indoor sowing: zucchini

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. Start harvesting zucchini

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

To set up a strong June, finish these tasks
  • First harvests: zucchini

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Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Sussex County, New Jersey is in USDA Zone 6b. 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 174 feet, Sussex County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Zucchini during the growing season.

Sussex County, NJ (Zone 6b) Long season
228 days
Last Spring Frost March 29
228 growing days
First Fall Frost November 12

Sussex County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (109 days to spare)
Start indoors: Feb 18 Transplant: Apr 8 🍅 Harvest: May 27 – Jul 22
Recommended (50%) ✓ Fits season (109 days to spare)
Start indoors: Feb 22 Transplant: Apr 12 🍅 Harvest: May 31 – Jul 26
Safe Start (90%) ✓ Fits season (118 days to spare)
Start indoors: Mar 5 Transplant: Apr 23 🍅 Harvest: Jun 11 – Aug 6

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.

Soil Compatibility in Sussex County

How your county's soil matches Zucchini's growing requirements.

Soil pH

Your soil pH (4.8–6.4) is more acidic than Zucchini prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Sussex County is excellent for Zucchini — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Zucchini.

How to Plant Zucchini

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Zucchini

6
successive plantings in your 228-day season

Sow every 5.1 weeks. Last sowing by Sep 13 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.7″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 977 gal / 100 sq ft

Monthly Watering Guide for Zucchini

Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Zucchini Needs Rainfall You Supplement Action
Jan 2.6" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 5.2" 3.1" 2.1" 💧 Light watering
Apr 5.2" 3.1" 2.1" 💧 Light watering
May 5.2" 3.2" 2" 💧 Light watering
Jun 5.2" 3.4" 1.8" 💧 Light watering
Jul 5.2" 3.9" 1.3" 💧 Light watering
Aug 5.2" 3.8" 1.4" 💧 Light watering
Sep 5.2" 3.1" 2.1" 💧 Light watering
Oct 5.2" 3.4" 1.8" 💧 Light watering
Nov 5.2" 3.5" 1.7" 💧 Light watering
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Sussex County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Zucchini Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Zucchini needs ~761 GDD — county provides 3,306 GDD Excellent fit

Zucchini Planting Timeline — Sussex County, NJ

Zucchini Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors April 12 Apr 12 – Apr 26
Direct Sow April 5 Apr 5 – Apr 26
Harvest May 31 May 31 – Jul 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 1-2 times/week

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

228 days in Sussex County

Growing Tips for Zucchini in Sussex County

Direct sow Zucchini outdoors after March 29 in Sussex County when soil has warmed and frost danger has passed.

Your generous 228.0-day season in Sussex County allows multiple plantings of Zucchini. Sow every 22.0 days for continuous harvest.

Common pests for Zucchini in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in Sussex County, NJ?

Sussex County is in Zone 6b with an average last frost of March 29. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sussex County, NJ?

Sussex County, New Jersey is in USDA Hardiness Zone 6b. The average last spring frost is March 29 and first fall frost is November 12.

🌱

Your Sussex County Garden Planner — Free

A 24-page printable planner built for Sussex County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.