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When to Plant Amaranth in King William County, VA

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.

King William County, Virginia is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is November 2, giving you a growing season of approximately 210 days.

At an elevation of 110 feet, King William County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94ยฐF, providing good warmth for Amaranth during the growing season.

King William County, VA (Zone 7a) Long season
210 days
Last Spring Frost April 6
210 growing days
First Fall Frost November 2

King William 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 (58 days to spare)
Start indoors: Feb 8 Transplant: Apr 12 🍅 Harvest: Jul 12 – Aug 30
Recommended (50%) ✓ Fits season (56 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Jul 20 – Sep 7
Safe Start (90%) ✓ Fits season (57 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 King William County

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

Soil pH

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

Soil Texture

The silt loam soil in King William County is excellent for Amaranth โ€” 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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 348 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 โ€” 3.2" 0" โ„๏ธ Dormant
Feb โ€” 3.3" 0" โ„๏ธ Dormant
Mar โ€” 3.5" 0" โ„๏ธ Dormant
Apr 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
May 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Jun 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Jul 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Aug 4.3" 4.5" 0" โœ… Rainfall sufficient
Sep 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Oct 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Nov 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Dec โ€” 3.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in King William 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 ~2,152 GDD — county provides 4,305 GDD Excellent fit

Amaranth Planting Timeline โ€” King William County, VA

Amaranth Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 โ€“ Mar 2
Transplant Outdoors April 20 Apr 20 โ€“ May 4
Direct Sow April 13 Apr 13 โ€“ May 4
Harvest July 20 Jul 20 โ€“ Sep 7

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Harvest
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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

210 days in King William County

Growing Tips for Amaranth in King William County

Direct sow Amaranth outdoors after April 06 in King William 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 King William County, VA?

King William County is in Zone 7a with an average last frost of April 6. Plan your Amaranth planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is King William County, VA?

King William County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help King William County gardeners in Zone 7a 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 King William County, VA. Local conditions may vary. Last updated: April 2026.