Smooth Pigweed

Biological Name:

Amaranthus retroflexus (Smooth-Pigweed)

Natural Habitat:

Smooth-Pigweed: This plant is native to North America and can be found in a variety of habitats, including fields, roadsides, and waste areas.


Smooth-Pigweed also known as Amaranthus is a plant that is native to grassland and prairie regions of North America. It is an annual herb that can grow up to six feet tall and it has small oval-shaped leaves and small inconspicuous flowers that are typically green or yellow in color. The plant is known for its smooth hairless leaves and it is often found in disturbed or degraded habitats.

Frequently Asked Questions (FAQs)

Q: Is smooth pigweed edible?
A: The leaves of pigweed are also incredibly nutritious. They’re high in vitamins A and C and folate, as well as calcium. In Jamaica, pigweed is known as callaloo and is a culinary staple.

Q: Why do they call it pigweed?
A: Their common name, pigweed, may have comes from its use as fodder for pigs. Pigweed plants are commonly considered to be weeds by farmers and gardeners because they thrive in disturbed soils.

Q: How do you prepare pigweed for eating?
A: Place the pigweed in a medium saucepan on low heat. Cover with a lid and cook for a couple of minutes until wilted. Add a tablespoon of water if you wish to help it steam. Remove from heat and drain in a colander.

Q: What is the difference between pigweed and amaranth?
A: Smooth pigweed has a more rounded first leaf than Powell amaranth. Readily distinguished from redroot pigweed only when mature. Very small fine hairs are found throughout plant. Flowering structure is highly branched, more so than redroot pigweed or Powell amaranth.

Q: Why is pigweed so difficult to control?
A: The researchers have determined a specific genetic feature, the extrachromosomal circular DNA (eccDNA) replicon, gives pigweed, or glyphosate resistant palmer amaranth, its resistance to glyphosate and makes this weed difficult to control.

Q: Should I remove pigweed?
A: If you spot pigweed plants that have yet to produce mature seeds, pull them or cut them off just below the soil line. Plants with mature seeds should be bagged before being removed and destroyed. Either burn the plants or bury them under at least a foot of compost.

Q: Does pigweed come back every year?
A: Prostrate pigweed — AKA mat amaranth, prostrate amaranth or spreading pigweed — is a summer annual that acts like a perennial. Although it completes its life cycle in one growing season, it can come back year after year, seemingly resisting any attempts to eradicate it.

Q: Does Roundup work on pigweed?
A: Pigheaded pigweed- an amaranth that can’t be killed by Roundup – Plants and Pipettes.

Q: How do you stop pigweed?
A: One of the best ways to prevent spiny pigweed is by using a pre-emergence herbicide containing the active ingredient trifluralin. Treflan is one of the well-known brands, Preen and Eliminator also make trifluralin products. Pre-emergent herbicides work by preventing weed seeds from germinating.

Q: What is the scientific name for smooth pigweed?
A: ”

Q: What part of pigweed is poisonous?
A: Pigweed (Amaranthus retroflexus) is a common annual weed found throughout the United States. The weed can grow three to four feet; the flowers are green and prickly and the plant has oval shaped leaves. The pigweed’s leaves, roots and stems are toxic.

Q: Is pigweed poisonous to humans?
A: Yes, the weeds in the garden we call pigweed, including prostrate pigweed, from the amaranth family, are edible. Every part of the plant can be eaten, but the young leaves and growing tips on older plants are the tastiest and most tender. The seeds are nutritious, edible, and are not difficult to harvest.

Q: Should you pull pigweed?
A: If pigweeds are in the advanced reproductive stage and might drop viable seed when handled, carefully bagging plants is even more important, Farr and others say. Guy Collins, cotton Extension associate professor at North Carolina State University, also advocates hand pulling.

Q: What damage does pigweed do?
A: Gross lesions of pigweed toxicosis include widespread edema, most prominently around the kidneys, rectum and omentum. Kidneys are pale and normal to swollen in size. Histopathologic changes within the kidney include interstitial edema, scattered hemorrhages and proximal tubular degeneration and necrosis.

Q: Can you eat raw pigweed?
A: Pigweed can grow to 2-3 metres high and are generally found in gardens, cultivated or abandoned fields. The leaves can be eaten raw or cooked like spinach, due to its mild flavour, it is adaptable to many dishes.

Q: What time of year does pigweed grow?
A: Season of emergence: These species emerge mainly in late spring and early summer but continue to emerge throughout the growing season, particularly after soil disturbance. Redroot pigweed and smooth pigweed are classified as late emerging weeds with a relatively long (approximately two month) emergence duration.

Q: What is another name for pigweed?
A: Amaranthus retroflexus is a species of flowering plant in the family Amaranthaceae with several common names, including red-root amaranth, redroot pigweed, red-rooted pigweed, common amaranth, pigweed amaranth, and common tumbleweed.

Q: What is pigweed good for?
A: Consuming pigweed can help alleviate fever, headache, nausea, stomachache, and other digestive disorders. Moreover, pigweed leaves have astringent properties. For that reason, tea made from these leaves can help treat sore throat, heavy menstrual bleeding, diarrhea, internal bleeding, and internal ulcers.

Q: What states does pigweed grow?
A: Redroot pigweed (Amaranthus retroflexus) Redroot pigweed, a summer annual broadleaf plant, is found up to 7900 feet (2400 m) in the Central Valley, northwestern region, central-western region, southwestern region, Modoc Plateau, and most likely in other California areas.

About the author

Samuel is a gardening professional and enthusiast who has spent over 20 years advising homeowners and farm owners on weed identification, prevention and removal. He has an undergraduate degree in plant and soil science from Michigan State University.