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When to Plant Sunflower in Ocean County, NJ

Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Ocean County, New Jersey is in USDA Zone 7a. The average last spring frost is April 12 and the first fall frost is October 31, giving you a growing season of approximately 202 days.

At an elevation of 82 feet, Ocean County receives approximately 44 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Sunflower during the growing season.

Ocean County, NJ (Zone 7a) Long season
202 days
Last Spring Frost April 12
202 growing days
First Fall Frost October 31

Ocean 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 (67 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jun 25 – Aug 13
Recommended (50%) ✓ Fits season (69 days to spare)
Start indoors: Feb 22 Transplant: Apr 26 🍅 Harvest: Jul 5 – Aug 23
Safe Start (90%) ✓ Fits season (80 days to spare)
Start indoors: Mar 13 Transplant: May 15 🍅 Harvest: Jul 24 – Sep 11

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 Ocean County

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

Soil pH

Your soil pH (5.0โ€“6.6) is more acidic than Sunflower prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Ocean County is excellent for Sunflower โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

3
successive plantings in your 202-day season

Sow every 8 weeks. Last sowing by Jul 23 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sunflower

Sunflower needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Sunflower Needs Rainfall You Supplement Action
Jan โ€” 3" 0" โ„๏ธ Dormant
Feb โ€” 3.1" 0" โ„๏ธ Dormant
Mar โ€” 3.9" 0" โ„๏ธ Dormant
Apr 2.2" 3.9" 0" โœ… Rainfall sufficient
May 2.2" 3.9" 0" โœ… Rainfall sufficient
Jun 2.2" 3.9" 0" โœ… Rainfall sufficient
Jul 2.2" 4.8" 0" โœ… Rainfall sufficient
Aug 2.2" 3.6" 0" โœ… Rainfall sufficient
Sep 2.2" 4" 0" โœ… Rainfall sufficient
Oct 2.2" 3.4" 0" โœ… Rainfall sufficient
Nov โ€” 3.7" 0" โ„๏ธ Dormant
Dec โ€” 2.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Ocean County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Sunflower 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" โ€” every day above 50ยฐF 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.

Sunflower needs ~1,424 GDD — county provides 3,383 GDD Excellent fit

Sunflower Planting Timeline โ€” Ocean County, NJ

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 โ€“ Mar 8
Transplant Outdoors April 26 Apr 26 โ€“ May 10
Direct Sow April 19 Apr 19 โ€“ May 10
Harvest July 5 Jul 5 โ€“ Aug 23

Plant 1" deep ยท 18" apart ยท Rows 30" 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 โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

202 days in Ocean County

Growing Tips for Sunflower in Ocean County

Direct sow Sunflower outdoors after April 12 in Ocean County when soil has warmed and frost danger has passed.

Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Ocean County, NJ?

Ocean County is in Zone 7a with an average last frost of April 12. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Ocean County, NJ?

Ocean County, New Jersey is in USDA Hardiness Zone 7a. The average last spring frost is April 12 and first fall frost is October 31.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Ocean 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 Ocean County, NJ. Local conditions may vary. Last updated: April 2026.