Blog

When to Plant Amaranth in Robeson County, NC

Robeson County, North Carolina Zone 8b May

Your May gardening checklist

Your Robeson County, North 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 24
Avg. first frost November 6
Soil temp (4") 71°F
Watering Moderate
Pest pressure High
Daylight 13.8 hrs
  1. Sow amaranth in trays indoors

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

Instant PDF download. No spam, unsubscribe any time.

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.

Robeson County, North Carolina is in USDA Zone 8b. The average last spring frost is March 24 and the first fall frost is November 6, giving you a growing season of approximately 227 days.

At an elevation of 887 feet, Robeson County receives approximately 49.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 97°F, so Amaranth may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Amaranth, but amend with compost to improve drainage and prevent root rot.

Robeson County, NC (Zone 8b) Long season
227 days
Last Spring Frost March 24
227 growing days
First Fall Frost November 6

Robeson County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Jan 26 Transplant: Mar 30 🍅 Harvest: Jun 29 – Aug 17
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Feb 3 Transplant: Apr 7 🍅 Harvest: Jul 7 – Aug 25
Safe Start (90%) ✓ Fits season (67 days to spare)
Start indoors: Feb 26 Transplant: Apr 30 🍅 Harvest: Jul 30 – Sep 17

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 Robeson County

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

Soil pH

Your soil pH (5.3–6.2) is more acidic than Amaranth prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Robeson County is excellent for Amaranth — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). 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
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 195 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 3.7" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.3" 4.9" 0" ✅ Rainfall sufficient
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.3" 0" ✅ Rainfall sufficient
Sep 4.3" 3.9" 0.4" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 4.3" 3.3" 1" 💧 Light watering
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Robeson 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 5,164 GDD Excellent fit

Amaranth Planting Timeline — Robeson County, NC

Amaranth Planting Calendar

Activity When Date Range
Start Indoors February 3 Feb 3 – Feb 17
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 31 Mar 31 – Apr 21
Harvest July 7 Jul 7 – Aug 25

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 · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

227 days in Robeson County

Growing Tips for Amaranth in Robeson County

Direct sow Amaranth outdoors after March 24 in Robeson County when soil has warmed and frost danger has passed.

With Robeson County's clay soil (31% clay), work in 3-4 inches of compost before planting Amaranth. Avoid tilling when soil is wet to prevent compaction.

With summer highs reaching 97°F in Robeson 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 Robeson County, NC?

Robeson County is in Zone 8b with an average last frost of March 24. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.

What planting zone is Robeson County, NC?

Robeson County, North Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 24 and first fall frost is November 6.

🌱

Your Robeson County Garden Planner — Free

A 24-page printable planner built for Robeson 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 Robeson County, NC. 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.