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When to Plant Amaranth in Barnwell County, SC

Barnwell County, South Carolina Zone 8b May

May in Barnwell County, South Carolina — your action list

Here's what deserves your attention in Barnwell County, South Carolina this month. Everything below is tailored to Zone 8b and timed around your local frost dates.

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

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

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Amaranth is an ancient grain crop with edible leaves and seeds, rich in protein and micronutrients. It thrives in warm conditions and is drought-tolerant once established.

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 Amaranth may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Amaranth 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 (82 days to spare)
Start indoors: Jan 21 Transplant: Mar 25 🍅 Harvest: Jun 24 – Aug 12
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Feb 1 Transplant: Apr 5 🍅 Harvest: Jul 5 – Aug 23
Safe Start (90%) ✓ Fits season (79 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Jul 22 – Sep 9

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 Amaranth's growing requirements.

Soil pH

Your soil pH (5.0–6.3) is more acidic than Amaranth prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Amaranth.

Organic Matter

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

How to Plant Amaranth

1"
Planting Depth
15"
Between Plants
24"
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 Amaranth

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

Month Amaranth 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.

Amaranth 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.

Amaranth needs ~2,389 GDD — county provides 5,300 GDD Excellent fit

Amaranth Planting Timeline — Barnwell County, SC

Amaranth Planting Calendar

Activity When Date Range
Start Indoors February 1 Feb 1 – Feb 15
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow March 29 Mar 29 – Apr 19
Harvest July 5 Jul 5 – Aug 23

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

233 days in Barnwell County

Growing Tips for Amaranth in Barnwell County

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

Sandy soil in Barnwell County dries quickly — mulch Amaranth 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 Amaranth and water deeply in the morning.

General growing tips

Direct sow after last frost when soil is warm. Thin seedlings to 18 inches apart. Harvest leaves when young and tender; harvest seeds when flower heads begin to dry.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Amaranth in Barnwell County, SC?

Barnwell County is in Zone 8b with an average last frost of March 22. Plan your Amaranth 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.

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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.