Blog

When to Plant Amaranth in Hamlin County, SD

Hamlin County, South Dakota Zone 4b May

Top priorities for Hamlin County, South Dakota gardeners in May

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

Avg. last frost May 6
Avg. first frost October 3
Soil temp (4") 52°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Harden off and plant amaranth

    Your last frost (May 6) has passed. These warm-season crops can handle outdoor soil now.

  2. Sow amaranth where they'll grow

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

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.

Hamlin County, South Dakota is in USDA Zone 4b. The average last spring frost is May 6 and the first fall frost is October 3, giving you a growing season of approximately 150 days.

At an elevation of 729 feet, Hamlin County receives approximately 24.8 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Amaranth to ensure they mature before fall.

Hamlin County, SD (Zone 4b) Moderate season
150 days
Last Spring Frost May 6
150 growing days
First Fall Frost October 3
Share this guide:

Hamlin County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 23 Transplant: May 18 🍅 Harvest: Aug 17 – Oct 5
Recommended (50%) ✗ May not fit
Start indoors: Mar 4 Transplant: May 27 🍅 Harvest: Aug 26 – Oct 14
Safe Start (90%) ✗ May not fit
Start indoors: Mar 13 Transplant: Jun 5 🍅 Harvest: Sep 4 – Oct 23

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 Hamlin County

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

Soil pH

Your soil pH (6.7–7.7) overlaps with Amaranth's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Amaranth.

Organic Matter

Organic matter is moderate (3.5%). 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
0.7″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 970 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 0.7" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 3.4" 0.9" 💧 Light watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 2.6" 1.7" 💧 Light watering
Oct 4.3" 1.5" 2.8" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Hamlin 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 ~1,365 GDD — county provides 1,950 GDD Excellent fit

Amaranth Planting Timeline — Hamlin County, SD

Amaranth Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors May 27 May 27 – Jun 10
Direct Sow May 20 May 20 – Jun 10
Harvest August 26 Aug 26 – Oct 14

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

150 days in Hamlin County

Growing Tips for Amaranth in Hamlin County

Direct sow Amaranth outdoors after May 06 in Hamlin County when soil has warmed and frost danger has passed.

Hamlin County receives only 25" of rain annually. Amaranth needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Hamlin County, SD?

Hamlin County is in Zone 4b with an average last frost of May 6. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamlin County, SD?

Hamlin County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 6 and first fall frost is October 3.

🌱

Your Hamlin County Garden Planner — Free

A 24-page printable planner built for Hamlin County (Zone 4b). 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 Hamlin County, SD. 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.