Southern Amaranth, Giant Amaranth, Pigweed

Amaranthus australis

Family: Amaranthaceae
Genus: Amaranthus (am-uh-RANTH-us) (Info)
Species: australis (aw-STRAL-iss) (Info)
Synonym:Acnida alabamensis
Synonym:Acnida australis
Synonym:Acnida cuspidata




Foliage Color:

Unknown - Tell us

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Requires consistently moist soil; do not let dry out between waterings

Where to Grow:

Unknown - Tell us


6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)


Unknown - Tell us


USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Sun to Partial Shade



Bloom Color:

Pale Yellow

Bloom Time:

Blooms all year


Unknown - Tell us

Other details:

May be a noxious weed or invasive

Soil pH requirements:

Unknown - Tell us

Patent Information:


Propagation Methods:

From herbaceous stem cuttings

From seed; direct sow after last frost

Seed Collecting:

Unknown - Tell us


This plant has been said to grow in the following regions:

Tuskegee, Alabama

Alachua, Florida

Apopka, Florida

Carrollton, Georgia

Trout, Louisiana

Trenton, New Jersey

Austin, Texas

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Gardeners' Notes:


On Dec 28, 2012, SilkKnoll from Tuskegee, AL (Zone 8a) wrote:

Southern amaranth is native here. It sometimes wanders into my vegetable garden, but it's easy to pull, and, after its long tap root brings up nutrients from far deeper than vegetables would ever reach, the plant makes excellent compost. Before the stalk dries, it's easy to chop up with a machete or cut up with loppers. Then it can be worked back into the soil on the spot.

The leaves make good, spinach-like pot greens, and the seeds can be collected to make sprouts. The tender, young greens are good in salads or on sandwiches. Even for cooking, it's best to harvest young, I find. I grow other varieties for cooking, but they all are the most tender and the easiest to harvest when they are about a foot tall.

Amaranth was among the first cultivated plants in the ... read more


On Aug 14, 2012, markkromer from Apopka, FL wrote:

This plant is HUGE and loves damp, rich soil. The stem is usually hollow. The plant is so tall it stands out amongst all other plants and may be mistaken for a small tree. I have not found anything useful about it, though.


On Mar 27, 2011, Campfiredan from Alachua, FL (Zone 8b) wrote:

This grows wild in my area around Gainesville Fl. Does anyone know if it is edible (seeds or leaves) or have any information indicating it was used as food for Native Americans? A good reference document listing it as edible or used as food would be helpful.


On Jan 11, 2005, Floridian from Lutz, FL (Zone 9b) wrote:

Herbaceous, short-lived perennial with a stout stem that grows to about 1 foot tall. The leaves are alternate on long red or green petioles. The leaves are 4 to 12 inches lone and 2 to 4 inches wide. Theyre widest at the base and taper to a point. The plant blooms small yellow flowers along branched, terminal or axillary stalks all year.

Its natural habitat is brackish and freshwater marshes from Florida to Louisiana, Mexico and the West Indies