Ornamental · Amaranthaceae
Amaranth
Amaranthus caudatus
Give it full sun and warm soil, and amaranth spins out long rope-like tassels from summer into fall.
Full sun
USDA 2–11
3–5 ft · 0.9–1.5 m
Overview
Up close, amaranth is all texture and color. The ornamental favorite, Love-Lies-Bleeding, drops long, rope-like tassels of crimson or gold, dense plush cords of tiny flowers that trail almost to the ground and sway with any breeze. Broad, veined leaves climb the stout stems beneath them, and the whole easy annual asks for little beyond warmth and sun.
Look at the genus side by side and the differences stand out. Some kinds spill their plumes downward in deep reds, greens, and golds, while others hold their heads bolt upright. The grain types pack tight clusters of small, pale edible seeds into those upright heads, and the weedy pigweeds, leaves coarser and flowers duller, share the same genus.
On the plant itself the leaves are what carry the catch. The foliage can hold high nitrates, hidden in the green of leaves that otherwise look entirely ordinary, and that matters where grazing animals reach the plant. The flowers and seed heads are the showpiece, but the broad leaves are where the chemistry sits.
Care
The short version: set amaranth in full sun and well-drained, moist soil, keep it watered while it roots in, feed it sparingly, and stake the tall, heavy-headed kinds once their flower spikes form.
Light
Give amaranth full sun and the tassels deepen to their richest red or gold while the stems thicken and stand firm. A little afternoon shade is fine, but heavier shade leaves you with thin, pale stems and skimpy, sparse flower spikes.
Water
Keep the soil evenly moist while the young plants push out their first roots and leaves. Once settled they ride out a dry stretch, though steady water fills the spikes out longest and plumpest.
Soil
Amaranth wants well-drained, moist soil and little more. Sharp drainage counts the most, since waterlogged ground around the roots is what brings on rot.
Humidity
Plain outdoor air suits amaranth, so there is no level to chase. Good airflow through the broad leaves does more, drying their surfaces and keeping leaf spot off them.
Feeding
Amaranth wants little feeding and colors up best in lean ground. Keep nitrogen low above all, since a heavy feed swells soft, floppy growth and drives the leaves to stockpile nitrates.
Pruning
There is barely any cutting to do. Deadhead or cut the spikes while the tassels are full for fresh or dried arrangements, and stake the tall kinds once the heavy heads weigh the stems down.
Size & spacing
The stems climb 3 to 5 feet (91 to 152 cm) tall and the leafy spread fills 12 to 24 inches (30 to 61 cm) across. Give the tall kinds room to stand and air to slip between the leaves.
When to plant
Amaranth is a warm-season annual that frost will cut down, so its growth waits on the warmth. Start seed indoors in early spring or sow it straight in the bed once the cold lifts, and the spikes color up from midsummer into fall, about three months after sowing.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 6 to 8 weeks before last frost, or direct sow after last frost
- Plant: After danger of last frost has passed
- Harvest: Blooms summer through fall; flowering begins about 3 months after sowing
Hardiness
USDA hardiness zones: 2–11
Temperature: down to -46°C
Troubleshooting
Amaranth holds its health through most of the season, and the few troubles it meets show on the broad leaves, the long flower spikes, or the roots below. Match the look of your plant to the cases below, then act before the damage widens.
A slumping stem gone dark and soft at the soil
Roots left in soggy ground fall to Phytophthora blight and root rot, which leaves the lower stem and roots blackened and mushy to the touch until the whole plant sags over. Wood gone this soft holds no life, so the plant is pulled and destroyed. The drainage is opened up before anything is set back in that ground.
Fix:
- Remove and destroy affected plants
- Improve soil drainage
Dark, sharp-cornered blotches penned in by veins
Dark blotches that look water-soaked and turn angular where the veins fence them in, often rimmed by a yellow halo, mark bacterial leaf spot. Each spotted leaf is picked off the moment the marks appear. Water aimed low at the soil keeps the broad leaf surfaces dry, and a dry leaf gives the bacteria no film to creep across.
Fix:
- Remove affected foliage
- Avoid overhead watering to reduce leaf wetness
A glossy film with shoots that twist and pucker
When the young leaves curl and a glossy, tacky film coats them, aphids are at work. Look closely along the flower spikes and under the leaves, where pinhead-sized soft green bodies cluster in their own sticky honeydew. A hard spray of water knocks the soft insects clean off, and insecticidal soap clears any thick colony that holds on.
Fix:
- Spray off with a strong jet of water
- Apply insecticidal soap if populations are heavy
Toxicity
Amaranth is safe to grow around cats and dogs, which the ASPCA lists as non-toxic. The real concern sits in the leaves of grazing animals' reach: the foliage can store up nitrates and oxalates, and a livestock animal eating a large amount of stressed leaves can be poisoned. Keep cattle, horses, and other grazers off big stands of it.
Toxic to
Horses · Rabbits · Livestock · Birds · People
Safe for
Cats · Dogs
Horses Caution
The ASPCA lists amaranth as non-toxic to horses, but a horse crops mouthfuls at a time, and leaves carrying high nitrates can still trouble a grazing animal. Keep them clear of a broad stand of it, above all once a dry spell has set in.
Rabbits Caution
A nibbled leaf or two seldom harms a rabbit, but the nitrates and oxalates that affect grazing stock collect in the foliage all the same. Let it be a rare taste, not a daily part of the diet.
Livestock Severe
Nitrate poisoning in cattle and other grazing animals: increased salivation, labored breathing, incoordination, weak pulse, muscle tremors, weakness, chocolate-brown blood, and death; signs appear about two to six hours after eating. Soluble oxalates and nephrotoxin can also cause kidney damage.
Birds Caution
Birds work over the ripe seed heads with relish, and that much is fine to leave them. Heavy feeding on the nitrate-rich leaves is the worry, so let them strip the seed and pass over the foliage.
People Caution
People raise amaranth for both grain and greens, and each is eaten cooked. The catch is the nitrates and oxalates that gather in leaves off stressed plants, so cook the greens and leave foliage from drought-hit plants alone.
Cats None
Cats can poke at the tassels with no trouble, since the ASPCA marks amaranth non-toxic to them and a curious nibble does no harm.
Dogs None
Dogs are clear around it as well. Amaranth holds a place on the ASPCA non-toxic list, so a leaf chewed off a low stem causes no harm.
Safe to grow around dogs and cats; the main risk is to grazing animals eating large amounts of foliage, especially under drought stress or high soil nitrogen.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Amaranth ranges from trailing, tassel-heavy ornamentals to stiff, upright grain crops. These are the kinds you are most likely to come across.
Amaranthus caudatus (Love-Lies-Bleeding)
The classic ornamental, strung with long, rope-like tassels of deep red or gold that hang and trail toward the ground.
'Viridis'
A green-flowered Love-Lies-Bleeding whose tassels glow a soft, unusual chartreuse.
Amaranthus cruentus
An upright grain and ornamental type whose plume-shaped flower heads stand erect above the leaves and ripen into edible seed.
Amaranthus hypochondriacus (Prince's Feather)
A tall, stiffly upright grain amaranth, and the species the ASPCA lists as non-toxic to cats and dogs.
How to propagate
Amaranth is one of the simplest plants to raise from its tiny seed, and once grown it scatters that seed and comes up around the garden on its own.
SeedEasy
Sow indoors 6 to 8 weeks before last frost, or direct sow outdoors after last frost. · Flowering begins roughly 3 months after sowing
From tiny, hard seed amaranth comes up readily and scatters its own seed around the bed once established. Start it indoors 6 to 8 weeks before your last frost, or sow it straight where it is to grow once the frost danger has passed. Thin or set out the seedlings, and the first slim tassels begin to lengthen about three months later.
Myths
Amaranth flowers are poisonous to cats and dogs.
The colored tassels look striking but carry no threat to pets, since the ASPCA lists amaranth as non-toxic to cats, dogs, and horses. The documented risk falls on grazing livestock, where nitrate and oxalate buildup in the leaves is what does the harm.
Amaranth is edible, so any animal can graze it freely.
Pigweeds in this genus pull nitrates and soluble oxalates into their leaves and rank among the leading causes of nitrate poisoning in cattle. Drought stress and high nitrogen push those levels highest, which is exactly when a grazing animal is most at risk.