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When to Plant Amaranth in Madison County, TN

Madison County, Tennessee Zone 7b May

May to-do list for Madison County, Tennessee

Your garden in Madison County, Tennessee is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 2
Avg. first frost October 28
Soil temp (4") 66°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Begin indoor sowing: amaranth

    These need a head start before your last frost (April 2). Sow into cells now so you're ready to transplant in a few weeks.

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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.

Madison County, Tennessee is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is October 28, giving you a growing season of approximately 209 days.

At an elevation of 1,852 feet, Madison County receives approximately 46.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Amaranth during the growing season.

Madison County, TN (Zone 7b) Long season
209 days
Last Spring Frost April 2
209 growing days
First Fall Frost October 28
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Madison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Start indoors: Feb 5 Transplant: Apr 9 🍅 Harvest: Jul 9 – Aug 27
Recommended (50%) ✓ Fits season (55 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jul 16 – Sep 3
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: Feb 28 Transplant: May 2 🍅 Harvest: Aug 1 – Sep 19

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 Madison County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Amaranth's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). 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 111 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 3.6" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.9" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Madison 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 ~1,759 GDD — county provides 3,500 GDD Excellent fit

Amaranth Planting Timeline — Madison County, TN

Amaranth Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 – Feb 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 9 Apr 9 – Apr 30
Harvest July 16 Jul 16 – Sep 3

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May
June
July Harvest
August Harvest
September Harvest
October
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: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

209 days in Madison County

Growing Tips for Amaranth in Madison County

Direct sow Amaranth outdoors after April 02 in Madison 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 Madison County, TN?

Madison County is in Zone 7b with an average last frost of April 2. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.

What planting zone is Madison County, TN?

Madison County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is October 28.

🌱

Your Madison County Garden Planner — Free

A 24-page printable planner built for Madison County (Zone 7b). 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 Madison County, TN. 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.