Blog

When to Plant Valerian in Barnwell County, SC

Barnwell County, South Carolina Zone 8b May

Top priorities for Barnwell County, South Carolina gardeners in May

Each item below is timed to Barnwell County, South Carolina's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 22
Avg. first frost November 10
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 13.7 hrs

Instant PDF download. No spam, unsubscribe any time.

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.

Barnwell County, South Carolina is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 10, giving you a growing season of approximately 233 days.

At an elevation of 157 feet, Barnwell County receives approximately 48.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Valerian may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Valerian will need more frequent watering and organic matter to retain nutrients.

Barnwell County, SC (Zone 8b) Long season
233 days
Last Spring Frost March 22
233 growing days
First Fall Frost November 10

Barnwell County Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Transplant: Mar 18 🍅 Harvest: Jul 22 – Oct 28
Recommended (50%) ✓ Fits season (2 days to spare)
Transplant: Mar 29 🍅 Harvest: Aug 2 – Nov 8
Safe Start (90%) ✓ Fits season (2 days to spare)
Transplant: Apr 15 🍅 Harvest: Aug 19 – Nov 25

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 Barnwell County

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

Soil pH

Your soil pH (5.0–6.3) overlaps with Valerian's range (5.5–7.0), though not a perfect match.

Soil Texture

Sandy soil in Barnwell County warms quickly in spring but drains fast. Valerian will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Valerian.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Valerian.

How to Plant Valerian

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

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

Monthly Watering Guide for Valerian

Valerian needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Valerian Needs Rainfall You Supplement Action
Jan 3.8" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.3" 4.5" 0" ✅ Rainfall sufficient
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 5.2" 0" ✅ Rainfall sufficient
Aug 4.3" 5" 0" ✅ Rainfall sufficient
Sep 4.3" 3.9" 0.4" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 4.3" 3.9" 0.4" 💧 Light watering
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Barnwell County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Valerian 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" — every day above 50°F 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.

Valerian needs ~3,412 GDD — county provides 5,300 GDD Excellent fit

Valerian Planting Timeline — Barnwell County, SC

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors March 29 Mar 29 – Apr 12
Harvest August 2 Aug 2 – Nov 8

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

233 days in Barnwell County

Growing Tips for Valerian in Barnwell County

Direct sow Valerian outdoors after March 22 in Barnwell County when soil has warmed and frost danger has passed.

Sandy soil in Barnwell County dries quickly — mulch Valerian with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 97°F in Barnwell County, provide afternoon shade for Valerian and water deeply in the morning.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Valerian in Barnwell County, SC?

Barnwell County is in Zone 8b with an average last frost of March 22. Plan your Valerian planting based on this frost date — see the calendar above for exact timing.

What planting zone is Barnwell County, SC?

Barnwell County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 10.

🌱

Your Barnwell County Garden Planner — Free

A 24-page printable planner built for Barnwell County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Barnwell County, SC. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.