Blog

When to Plant Valerian in Marlboro County, SC

Valerian is a tall perennial herb with fragrant white or pink flower clusters, valued for its root which is used as a natural sleep aid. It attracts pollinators and earthworms.

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 Valerian during the growing season. Clay soil retains moisture well for Valerian, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Valerian 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 (0 days to spare)
Transplant: Mar 23 🍅 Harvest: Jul 27 – Nov 2
Recommended (50%) ✗ May not fit
Transplant: Mar 30 🍅 Harvest: Aug 3 – Nov 9
Safe Start (90%) ✗ May not fit
Transplant: Apr 17 🍅 Harvest: Aug 21 – Nov 27

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
Valerian needs ~2,738 GDD — county provides 4,161 GDD Excellent fit

Valerian Planting Timeline โ€” Marlboro County, SC

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors March 30 Mar 30 โ€“ Apr 13
Harvest August 3 Aug 3 โ€“ Nov 9

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

120โ€“180 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 8a

Growing Season

228 days

Growing Tips for Marlboro County

Start seeds indoors and transplant after last frost. Harvest roots in fall of the second year. Deadhead flowers unless you want self-seeding. Cats are attracted to valerian root.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Valerian in Marlboro County, SC?

Marlboro County is in Zone 8a with an average last frost of March 23. Plan your Valerian 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.