Blog

When to plant Amaranth in Mapaville, MO

Mapaville gardeners should plant Amaranth between April 17 and May 8 in spring. With Mapaville's Zone 6b climate (last frost April 10), Amaranth needs 120 days to mature — plant by June 28 for a full harvest.

When to Plant Amaranth in Mapaville, MO

Jefferson County, Missouri Zone 6b June

Jefferson County, Missouri gardeners: here's your June plan

Each item below is timed to Jefferson County, Missouri's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 10
Avg. first frost October 26
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Sow amaranth in trays indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

July will be here before you know it — start on
  • 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.

Mapaville, Missouri is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 26, giving you a growing season of approximately 199 days.

At an elevation of 839 feet, Jefferson County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Amaranth during the growing season.

Mapaville, MO (Zone 6b) Moderate season
199 days
Last Spring Frost April 10
199 growing days
First Fall Frost October 26

Mapaville Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Amaranth Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Feb 7 Transplant: Apr 18 🍅 Harvest: Jul 18 – Sep 5
Recommended (50%) ✓ Fits season (45 days to spare)
Start indoors: Feb 13 Transplant: Apr 24 🍅 Harvest: Jul 24 – Sep 11
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Feb 26 Transplant: May 7 🍅 Harvest: Aug 6 – Sep 24

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 Mapaville

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

Soil pH

Your soil pH (5.7–7.1) overlaps with Amaranth's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). 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
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 515 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 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 3.2" 1.1" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jefferson 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 ~1,601 GDD — county provides 3,034 GDD Excellent fit

Amaranth Planting Timeline — Mapaville, MO

Amaranth Planting Calendar

Activity When Date Range
Start Indoors February 13 Feb 13 – Feb 27
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 17 Apr 17 – May 8
Harvest July 24 Jul 24 – Sep 11

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
September Harvest
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 6b

📆 Growing Season

199 days in Jefferson County

Growing Tips for Amaranth in Mapaville

Direct sow Amaranth outdoors after April 10 in Jefferson 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 →

When should I plant Amaranth in Mapaville, MO?

In Mapaville, MO, plant Amaranth after the last frost (around April 10) and before the first frost (around October 26). Best results when soil holds above 50°F.

What growing zone is Mapaville, MO for Amaranth?

Mapaville sits in USDA Zone 6b. Amaranth grows reliably in zones 2a through 11b, so it's a good fit here.

Can Amaranth grow in Mapaville's climate?

Yes — Amaranth grows well in Mapaville's temperate climate. Mapaville averages a 199-day frost-free season, with last frost around April 10 and first frost around October 26.

🌱

Your Jefferson County Garden Planner — Free

A 22-page printable planner built for Jefferson County (Zone 6b). 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 Jefferson County, MO. Local conditions may vary. Last updated: June 2026.