Blog

When to Plant Sunflower in Dorchester County, SC

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.

Dorchester County, South Carolina is in USDA Zone 8b. The average last spring frost is March 10 and the first fall frost is November 13, giving you a growing season of approximately 248 days.

At an elevation of 107 feet, Dorchester County receives approximately 49.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94ยฐF, providing good warmth for Sunflower during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Sunflower will need more frequent watering and organic matter to retain nutrients.

Dorchester County, SC (Zone 8b) Long season
248 days
Last Spring Frost March 10
248 growing days
First Fall Frost November 13

Dorchester County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (125 days to spare)
Start indoors: Jan 3 Transplant: Mar 7 🍅 Harvest: May 16 – Jul 4
Recommended (50%) ✓ Fits season (115 days to spare)
Start indoors: Jan 20 Transplant: Mar 24 🍅 Harvest: Jun 2 – Jul 21
Safe Start (90%) ✓ Fits season (117 days to spare)
Start indoors: Feb 17 Transplant: Apr 21 🍅 Harvest: Jun 30 – Aug 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.

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
Sunflower needs ~1,742 GDD — county provides 5,084 GDD Excellent fit

Sunflower Planting Timeline โ€” Dorchester County, SC

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 20 Jan 20 โ€“ Feb 3
Transplant Outdoors March 24 Mar 24 โ€“ Apr 7
Direct Sow March 17 Mar 17 โ€“ Apr 7
Harvest June 2 Jun 2 โ€“ Jul 21

Plant 1" deep ยท 18" apart ยท Rows 30" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 8b

Growing Season

248 days

Growing Tips for Dorchester County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunflower in Dorchester County, SC?

Dorchester County is in Zone 8b with an average last frost of March 10. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dorchester County, SC?

Dorchester County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 10 and first fall frost is November 13.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dorchester County gardeners in Zone 8b 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 Dorchester County, SC. Local conditions may vary. Last updated: April 2026.