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When to Plant Amaranth in Sumter County, SC

Sumter County, South Carolina Zone 8b May

This month in Sumter County, South Carolina

Your Sumter County, South Carolina garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 20
Avg. first frost November 15
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Fire up the seed-starting tray: amaranth

    Label every cell. You will absolutely forget which is which otherwise.

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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.

Sumter County, South Carolina is in USDA Zone 8b. The average last spring frost is March 20 and the first fall frost is November 15, giving you a growing season of approximately 240 days.

At an elevation of 163 feet, Sumter County receives approximately 59.6 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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Amaranth root diseases.

Sumter County, SC (Zone 8b) Long season
240 days
Last Spring Frost March 20
240 growing days
First Fall Frost November 15

Sumter County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.9-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Start indoors: Jan 19 Transplant: Mar 23 🍅 Harvest: Jun 22 – Aug 10
Recommended (50%) ✓ Fits season (86 days to spare)
Start indoors: Jan 30 Transplant: Apr 3 🍅 Harvest: Jul 3 – Aug 21
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jul 16 – Sep 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.

Soil Compatibility in Sumter County

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

Soil pH

Your soil pH (4.9–6.3) is more acidic than Amaranth prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Sumter 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
1.0″/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 4.8" 0" ❄️ Dormant
Feb 5.4" 0" ❄️ Dormant
Mar 4.3" 5.1" 0" ✅ Rainfall sufficient
Apr 4.3" 4.4" 0" ✅ Rainfall sufficient
May 4.3" 5.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 7" 0" ✅ Rainfall sufficient
Aug 4.3" 5.3" 0" ✅ Rainfall sufficient
Sep 4.3" 4.5" 0" ✅ Rainfall sufficient
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 4.2" 0.1" 💧 Light watering
Dec 5.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Sumter 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 5,460 GDD Excellent fit

Amaranth Planting Timeline — Sumter County, SC

Amaranth Planting Calendar

Activity When Date Range
Start Indoors January 30 Jan 30 – Feb 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 27 Mar 27 – Apr 17
Harvest July 3 Jul 3 – Aug 21

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
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

240 days in Sumter County

Growing Tips for Amaranth in Sumter County

Direct sow Amaranth outdoors after March 20 in Sumter County when soil has warmed and frost danger has passed.

Sandy soil in Sumter 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 Sumter 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 Sumter County, SC?

Sumter County is in Zone 8b with an average last frost of March 20. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sumter County, SC?

Sumter County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 20 and first fall frost is November 15.

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Your Sumter County Garden Planner — Free

A 24-page printable planner built for Sumter 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 Sumter 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.