Blog

When to plant Amaranth in Union County, AR

Aim to plant Amaranth in Union County on or after March 29; the window stays open through April 19. Union County's 226-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Amaranth in Union County, AR

Union County, Arkansas Zone 8b July

What to do in July

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 22
Avg. first frost November 3
Soil temp (4") 90°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Collect amaranth at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Before August arrives, get these ready
  • First harvests: amaranth

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.

Union County, Arkansas is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 3, giving you a growing season of approximately 226 days.

At an elevation of 508 feet, Union County receives approximately 52 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Amaranth during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Amaranth root diseases.

Union County, AR (Zone 8b) Long season
226 days
Last Spring Frost March 22
226 growing days
First Fall Frost November 3

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.6

Drainage

Well Drained

Amaranth Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Jan 23 Transplant: Mar 27 🍅 Harvest: Jun 26 – Aug 14
Recommended (50%) ✓ Fits season (72 days to spare)
Start indoors: Feb 1 Transplant: Apr 5 🍅 Harvest: Jul 5 – Aug 23
Safe Start (90%) ✓ Fits season (71 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jul 27 – Sep 14

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 Union County

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

Soil pH

Your soil pH (5.8–6.6) overlaps with Amaranth's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Amaranth.

How to Plant Amaranth

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Amaranth 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 68 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 4.5" 0" ❄️ Dormant
Mar 4.3" 4.5" 0" ✅ Rainfall sufficient
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 5.1" 0" ✅ Rainfall sufficient
Aug 4.3" 5.1" 0" ✅ Rainfall sufficient
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 4.3" 3.8" 0.5" 💧 Light watering
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Union 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 ~1,995 GDD — county provides 4,294 GDD Excellent fit

Amaranth Planting Timeline — Union County, AR

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 · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

226 days in Union County

Growing Tips for Amaranth in Union County

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

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 Union County, AR?

Union 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 Union County, AR?

Union County, Arkansas is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 3.

When should I plant Amaranth in Union County, AR?

In Union County, AR, plant Amaranth after the last frost (around March 22) and before the first frost (around November 3). Best results when soil holds above 50°F.

What growing zone is Union County, AR for Amaranth?

Union County sits in USDA Zone 8b. Amaranth grows reliably in zones 2a through 11b, so it's a good fit here.

Can Amaranth grow in Union County's climate?

Yes — Amaranth grows well in Union County's temperate climate. Union County averages a 226-day frost-free season, with last frost around March 22 and first frost around November 3.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union 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 Union County, AR. Local conditions may vary. Last updated: July 2026.

Sources & credits

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