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When to plant Amaranth in Washington County, ID

In Washington County, Amaranth is a spring-only crop. Plant May 16–June 6 once soil hits 50°F.

When to Plant Amaranth in Washington County, ID

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.

Washington County, Idaho is in USDA Zone 7a. The average last spring frost is May 9 and the first fall frost is October 1, giving you a growing season of approximately 145 days.

At an elevation of 4,048 feet, Washington County receives approximately 17.9 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Amaranth during the growing season. With low rainfall, drip irrigation is essential for growing Amaranth successfully. Mulch heavily to conserve soil moisture.

Washington County, ID (Zone 7a) Short season
145 days
Last Spring Frost May 9
145 growing days
First Fall Frost October 1

Washington County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Amaranth Planting Timeline — Washington County, ID

Amaranth Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 16 May 16 – Jun 6
Harvest August 22 Aug 22 – Oct 10

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

145 days in Washington County

Growing Tips for Washington County

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 Washington County, ID?

Washington County is in Zone 7a with an average last frost of May 9. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, ID?

Washington County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 9 and first fall frost is October 1.

When should I plant Amaranth in Washington County, ID?

In Washington County, ID, plant Amaranth after the last frost (around May 9) and before the first frost (around October 1). Best results when soil holds above 50°F.

What growing zone is Washington County, ID for Amaranth?

Washington County sits in USDA Zone 7a. Amaranth grows reliably in zones 2a through 11b, so it's a good fit here.

Can Amaranth grow in Washington County's climate?

Yes — Amaranth grows well in Washington County's temperate climate. Washington County averages a 145-day frost-free season, with last frost around May 9 and first frost around October 1.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 7a). 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 Washington County, ID. Local conditions may vary. Last updated: June 2026.

Sources & credits

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