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When to Plant Sunflower in Caroline County, VA

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.

Caroline County, Virginia is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.

At an elevation of 368 feet, Caroline County receives approximately 45.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Sunflower during the growing season.

Caroline County, VA (Zone 7a) Moderate season
193 days
Last Spring Frost April 14
193 growing days
First Fall Frost October 24

Caroline County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (62 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Jun 29 – Aug 17
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Feb 24 Transplant: Apr 28 🍅 Harvest: Jul 7 – Aug 25
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Mar 20 Transplant: May 22 🍅 Harvest: Jul 31 – Sep 18

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 Caroline County

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

Soil pH

Your soil pH (5.6โ€“6.8) overlaps with Sunflower's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). 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 193-day season

Sow every 8 weeks. Last sowing by Jul 16 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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€” 4" 0" โ„๏ธ Dormant
Feb โ€” 3.8" 0" โ„๏ธ Dormant
Mar โ€” 4.3" 0" โ„๏ธ Dormant
Apr 2.2" 2.9" 0" โœ… Rainfall sufficient
May 2.2" 3.3" 0" โœ… Rainfall sufficient
Jun 2.2" 3.5" 0" โœ… Rainfall sufficient
Jul 2.2" 4.6" 0" โœ… Rainfall sufficient
Aug 2.2" 4.8" 0" โœ… Rainfall sufficient
Sep 2.2" 3.5" 0" โœ… Rainfall sufficient
Oct 2.2" 3.1" 0" โœ… Rainfall sufficient
Nov โ€” 3.5" 0" โ„๏ธ Dormant
Dec โ€” 3.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Caroline 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 ~1,360 GDD — county provides 3,088 GDD Excellent fit

Sunflower Planting Timeline โ€” Caroline County, VA

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 โ€“ Mar 10
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest July 7 Jul 7 โ€“ Aug 25

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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

193 days in Caroline County

Growing Tips for Sunflower in Caroline County

Direct sow Sunflower outdoors after April 14 in Caroline 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 Caroline County, VA?

Caroline County is in Zone 7a with an average last frost of April 14. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Caroline County, VA?

Caroline County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

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