Blog

When to Plant Scallions in Marlboro County, SC

Scallions (green onions) are mild-flavored alliums harvested for their slender green tops and white bases. They are quick-growing and perfect for succession planting.

Marlboro County, South Carolina is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 6, giving you a growing season of approximately 228 days.

At an elevation of 132 feet, Marlboro County receives approximately 52.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91ยฐF, providing good warmth for Scallions during the growing season. Clay soil retains moisture well for Scallions, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Scallions root diseases.

Marlboro County, SC (Zone 8a) Long season
228 days
Last Spring Frost March 23
228 growing days
First Fall Frost November 6

Marlboro County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (147 days to spare)
Start indoors: Feb 9 Transplant: Mar 16 🍅 Harvest: May 11 – Jun 8
Recommended (50%) ✓ Fits season (144 days to spare)
Start indoors: Feb 16 Transplant: Mar 23 🍅 Harvest: May 18 – Jun 15
Safe Start (90%) ✓ Fits season (143 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 5 – Jul 3

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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 59 gal / 100 sq ft
Scallions needs ~1,095 GDD — county provides 4,161 GDD Excellent fit

Scallions Planting Timeline โ€” Marlboro County, SC

Scallions Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 โ€“ Mar 2
Transplant Outdoors March 23 Mar 23 โ€“ Apr 6
Direct Sow March 9 Mar 9 โ€“ Mar 30
Fall Sowing August 28 Aug 28 โ€“ Sep 11
Harvest May 18 May 18 โ€“ Jun 15

Plant 0.5" deep ยท 6" 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
May Harvest
June Harvest
July โ€”
August Fall Sowing
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

50โ€“70 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 8a

Growing Season

228 days

Growing Tips for Marlboro County

Direct sow every 3 weeks for continuous harvest. Thin to 1 inch apart or grow in clusters. Harvest when pencil-thick by pulling or cutting at soil level.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Level Up Your Garden

Frequently Asked Questions

When should I plant Scallions in Marlboro County, SC?

Marlboro County is in Zone 8a with an average last frost of March 23. Plan your Scallions planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marlboro County, SC?

Marlboro County, South Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 6.

๐ŸŒฑ

Plan Your Garden with Confidence

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