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When to Plant Amaranth in Marquette County, MI

Marquette County, Michigan Zone 5a May

Your May game plan for Marquette County, Michigan

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 10
Avg. first frost October 20
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14.8 hrs
  1. Get amaranth in the ground

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Scatter amaranth into prepared beds

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

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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.

Marquette County, Michigan is in USDA Zone 5a. The average last spring frost is May 10 and the first fall frost is October 20, giving you a growing season of approximately 163 days.

At an elevation of 564 feet, Marquette County receives approximately 36.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Amaranth to ensure they mature before fall.

Marquette County, MI (Zone 5a) Moderate season
163 days
Last Spring Frost May 10
163 growing days
First Fall Frost October 20
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Marquette County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Mar 7 Transplant: May 16 🍅 Harvest: Aug 15 – Oct 3
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Mar 15 Transplant: May 24 🍅 Harvest: Aug 23 – Oct 11
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Apr 1 Transplant: Jun 10 🍅 Harvest: Sep 9 – Oct 28

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 Marquette County

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

Soil pH

Your soil pH (6.0–6.8) is within Amaranth's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) — Amaranth will thrive.

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 104 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 1.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Marquette 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 ~1,129 GDD — county provides 1,752 GDD Excellent fit

Amaranth Planting Timeline — Marquette County, MI

Amaranth Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors May 24 May 24 – Jun 7
Direct Sow May 17 May 17 – Jun 7
Harvest August 23 Aug 23 – Oct 11

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
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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: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

163 days in Marquette County

Growing Tips for Amaranth in Marquette County

Direct sow Amaranth outdoors after May 10 in Marquette 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 Marquette County, MI?

Marquette County is in Zone 5a with an average last frost of May 10. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marquette County, MI?

Marquette County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 10 and first fall frost is October 20.

🌱

Your Marquette County Garden Planner — Free

A 24-page printable planner built for Marquette County (Zone 5a). 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 Marquette County, MI. 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.