How to Grow Amaranth: Planting, Spacing, Care & Harvest

Quick answer

Start indoors 3–4 weeks before last frost (UMN) or direct sow after last frost / soil >60°F (UNR). Not globe amaranth (Gomphrena).

Amaranth at a glance

PlantStart indoors: 4–3 wk before last frost; Direct sow: last frost
SunUMN: full sun; fertile, well-draining soil.
SpacingTiny seed — sow shallow.
Days to harvestLeaves ~40–59 days; seed ~90–100 days (UMN)
-5-4-3-2-1LF+1+2+3
■ Start indoors   ■ Plant out   ■ Harvest
Weeks relative to last frost (LF). Colored weeks show when our ZIP planner schedules each step.
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Planting dates for your ZIP: the ZIP planting planner counts each window from your local frost dates.

Organic pests and diseases: see also organic pest control. Use any product as the label directs.

Not globe amaranth: this page is vegetable/grain Amaranthus. Ornamental globe amaranth is Gomphrena — see planting guides for bedding flowers.

Amaranth leaves
Vegetable amaranth leaves (Amaranthus tricolor). Photo: Soramimi, Wikimedia Commons, CC BY-SA 4.0 (resized).

Planting timing

University of Minnesota CPBT: “Sow directly or start indoors 3–4 weeks before last frost.” Germination around 60°F soil. (UMN Amaranth sheet) University of Nevada Reno: amaranth is “not frost tolerant” and “should be planted when soil temperatures exceed 60 degrees Fahrenheit and after the last expected frost.” (UNR amaranth)

Depth and spacing

Tiny seed — sow shallow. Thin for leaf harvest; plants can grow tall and may need support. UMN notes weedy habits and a tendency to outcompete other plants — contain volunteers.

Sun, soil and water

UMN: full sun; fertile, well-draining soil. Warm-season crop.

Care

Harvest leaves continually once about 8 inches tall (UMN). Watch for self-seeding.

Harvest

UMN: leaf bunches about 40–59 days; seed about 90–100 days.

Pests and diseases

Cultural weed control matters — amaranth itself can behave weedy (UMN). Rotate and keep beds clean.

Related: ZIP planner · all grow guides · organic pest control

Frequently asked questions

When do I plant amaranth?

Indoors 3–4 weeks before last frost (UMN) or direct sow after last frost (UNR).

Is this globe amaranth?

No — globe amaranth is Gomphrena, a bedding flower.

Will it reseed?

UMN notes weedy habits — pick up seed heads if you do not want volunteers.

More grow guides: All grow guides

Sources