Is this plant a good choice for a home garden?

Generally no, as its sharp spines make it difficult to manage and it can quickly become an invasive weed.

How do I get rid of it?

Pull it by the roots before it sets seed, making sure to wear thick gloves to protect your hands from the spines.

Plant guide

Spiny amaranth.

Amaranthus spinosus

Pronounced am-uh-RAN-thus spy-NO-sus

Also known as Needle Burr, Prickly Callaloo, Prickly Careless Weed, Prince-of-Wales-feather, Soldier Weed, Spiny Amaranth

This hardy plant is often found growing as a weed in disturbed soils. It is known for its distinct sharp spines located at the base of its leaves. While it can be invasive, it is also harvested as a leafy green in some parts of the world.

At a glance

Care level: Easy
Plant type: Annual herb
Light: Full sun
Indoor light: Direct sun
Water: Every 3 to 7 days
Mature size: 3 to 4 feet
Growth rate: Fast
Hardiness: USDA 9 to 12
Bloom time: Mid summer to early autumn

Care

Give this plant plenty of sun and well-draining soil to keep it happy. Watch for wilting if the soil dries out completely, as it prefers consistent moisture. Be careful when handling it because the spines are quite sharp.

Watering: Keep the soil consistently moist but not waterlogged.
Feeding: Apply a balanced liquid fertilizer once a month during the growing season.
Pruning: Trim back any dead or damaged stems to encourage bushier growth.
Repotting: Repot only if the plant becomes root bound in its container.
Soil: Well-draining loamy soil
Soil pH: 6.0 to 7.5
Temperature: 10 to 35°C
Humidity: 40 to 70%

Safety

People: The plant is generally considered non-toxic, but the sharp spines pose a physical injury risk.
Pets: This plant is not considered highly toxic to cats and dogs, but it contains oxalates and can build up nitrates, so eating large amounts may cause stomach upset. Its sharp spines can also hurt mouths and paws.
Children: Keep children away from this plant because the sharp spines can easily pierce skin and cause painful injuries.
Contact allergens: The sharp spines can cause skin punctures and irritation upon contact.
Airborne allergens: The pollen may cause mild respiratory irritation in sensitive individuals.
Edibility: While young leaves are sometimes cooked as greens, they contain oxalates that can be harmful if consumed in large quantities or by those with kidney issues.

How to identify it

sharp spines at leaf bases
alternate green ovate leaves
small green flower clusters
stout branching stems

Height: 0.3 to 1m
Spread: 0.2 to 0.5m
Leaves: green, deciduous
Flowers: green, yellow, 0.2 to 0.5cm
Fruit: brown, Autumn

Problems to watch for

Aphids · Small insects that cluster on new growth and suck plant sap.

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: spring

This plant is best avoided in cultivated garden beds as it competes aggressively for nutrients.

Grows well with

Purslane · Both plants thrive in similar disturbed soil conditions.

Similar species

Redroot Pigweed · A related species that lacks the prominent spines of A. spinosus.

Science

Family: Amaranthaceae
Genus: Amaranthus
Order: Caryophyllales
Class: Magnoliopsida
Native range: Tropical and subtropical regions of the Americas.
Conservation: This species is a widespread, invasive weed in many parts of the world and is not of conservation concern.

It is a pioneer species that quickly colonizes disturbed ground and waste areas.

Value to wildlife: nectar source
Pollinators: bees, butterflies
Uses: traditional medicine, forage, green manure

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 6/9
Light: 8/9
Temperature: 8/9
Moisture: 5/9
Nutrients: 7/9

Taxonomy resolved against GBIF.

Questions people ask

Is this plant a good choice for a home garden?: Generally no, as its sharp spines make it difficult to manage and it can quickly become an invasive weed.
How do I get rid of it?: Pull it by the roots before it sets seed, making sure to wear thick gloves to protect your hands from the spines.

Where the name comes from

The genus name Amaranthus comes from the Greek word meaning unfading, while the species name spinosus highlights its characteristic spines.

Good to know

The specific epithet spinosus refers to the sharp spines found at the base of the leaf stalks.
It is highly adaptable and can thrive in disturbed soils where other plants struggle.
The plant produces a massive amount of seeds, ensuring its survival in harsh conditions.

Also in

Plants toxic to cats and dogs

Keep your spiny amaranth growing

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This guide was generated with AI on October 27, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.