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When to Plant Amaranth in Preble County, OH

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.

Preble County, Ohio is in USDA Zone 6a. The average last spring frost is April 24 and the first fall frost is October 21, giving you a growing season of approximately 180 days.

At an elevation of 1,250 feet, Preble County receives approximately 40 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Amaranth during the growing season.

Preble County, OH (Zone 6a) Moderate season
180 days
Last Spring Frost April 24
180 growing days
First Fall Frost October 21

Preble County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (27 days to spare)
Start indoors: Feb 18 Transplant: Apr 29 🍅 Harvest: Jul 29 – Sep 16
Recommended (50%) ✓ Fits season (26 days to spare)
Start indoors: Feb 27 Transplant: May 8 🍅 Harvest: Aug 7 – Sep 25
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: Mar 14 Transplant: May 23 🍅 Harvest: Aug 22 – Oct 10

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 Preble County

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

Soil pH

Your soil pH (6.0โ€“6.9) is within Amaranth's preferred range (6.0โ€“7.5).

Soil Texture

The silt loam soil in Preble County is excellent for Amaranth โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). 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 128 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar โ€” 2.8" 0" โ„๏ธ Dormant
Apr 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
May 4.3" 4.5" 0" โœ… Rainfall sufficient
Jun 4.3" 4.7" 0" โœ… Rainfall sufficient
Jul 4.3" 4.9" 0" โœ… Rainfall sufficient
Aug 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Sep 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Oct 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Nov โ€” 3" 0" โ„๏ธ Dormant
Dec โ€” 2.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Preble County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,916 GDD — county provides 3,285 GDD Excellent fit

Amaranth Planting Timeline โ€” Preble County, OH

Amaranth Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 โ€“ Mar 13
Transplant Outdoors May 8 May 8 โ€“ May 22
Direct Sow May 1 May 1 โ€“ May 22
Harvest August 7 Aug 7 โ€“ Sep 25

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June โ€”
July โ€”
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

180 days in Preble County

Growing Tips for Amaranth in Preble County

Direct sow Amaranth outdoors after April 24 in Preble 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 Preble County, OH?

Preble County is in Zone 6a with an average last frost of April 24. Plan your Amaranth planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Preble County, OH?

Preble County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 24 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Preble County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Preble County, OH. Local conditions may vary. Last updated: April 2026.