Amaranthus are vigorous annuals with an exotic appearance, divided into two main groups — those with erect plumes and those with long tassels of flowers, known by their highly descriptive name "love-lies-bleeding". They can be used to create vibrant bedding displays and be planted in mixed borders as well as in pots.
There are 60 species, native to many temperate and tropical regions. They are generally upright, bushy herbs 90-130cm tall, but there are also some that are spreading or prostrate. The species with plumes of flowers include A. cruentus, which has green or red leaves and a plume of dark-pink flowers.
Many varieties have been bred from this species. It is somewhat confusing botanically because it is also known by the synonym ?A. paniculatus, although not consistently, so the trade still lists many of the reddish foliage types with the latter name.
The second type of Amaranthus is perhaps more well recognised, with species such as A. caudatus that produces long drooping tassels of tiny flowers, often in shades of dark-red, earning it the common name love-lies-bleeding.
The species A. hypochondriacus is grown both for its flowers and foliage. The foliage is deeply flushed with purple and the flowers are plumes of crimson. A. tricolor is another interesting species because it produces plants with a range of brilliant leaf colours.
Varieties of note include A. tricolor ‘Molten Fire’, with browny/red leaves in the main but scarlet leaves in the centre, and A. tricolor ‘Joseph’s Coat’, like the technicolour dream coat made up of multiple colours — scarlet, gold, brown, yellow and green.
The amaranth flowers are very useful for florists too. They are partial to the green form of love-lies-bleeding — A. caudatus ‘Viridis’ — and often air dry flowers to create winter arrangements.
Growers of edible plants in the UK are also fond of the amaranths because the species A. caudatus, ?A. hypochondriacus and A. cruentus are all good to eat. The leaves taste like spinach and the seeds or "grains" are also edible. They were a staple food of the Aztecs and Incas and the plants are still cultivated today as a food source in South America, Africa, China, India, Nepal, Pakistan and Tibet.
The seeds are toasted like popcorn in Mexico and mixed with honey or molasses to make a treat called dulce de alegra, or sweet delight. The sticky grains are formed into skulls and eaten on the Day of the Dead.
Amaranthus are annuals so they are generally sown from seed in early spring under glass. But they can also be sown directly outdoors, where they are to flower. They prefer well-drained, well-worked, fertile soil, although A. caudatus can tolerate poor soil. Aphids are particularly fond of amaranths so some control may need to be carried out.
What the specialists say
Kevin Scott, managing director, Amati Plants, Dorset
"Amaranthus is a bold ornamental plant. They provide stunning red coloured foliage and dramatic plumes or tassels of flowers, which make great impact in flower borders and pots. Some species become giants, looking spectacular at the back of the border, like A. ‘Hopi Red Dye’ with its vibrant colour and ?A. ‘Golden Giant’ with its warm-toned plumes. Of course there are also the compact varieties of A. hypochondriacus, which make excellent bedding plants.
"It can be a nuisance due to its prolific self-seeding, but is probably worth the extra weeding. I recommend planting even the larger varieties in groups of three or more to make a really bold statement."
Kathy Moss, manager, The Seed Company, Kent
"Amaranthus seed is popular because they are annuals that can grow to a great height in a season and make a fantastic centrepiece in a seasonal display. They are interesting and exotic, and being from warmer climes they are best sown indoors if possible, around six-to-eight weeks before the last frosts so they can be planted out without being damaged.
"They can also be sown directly into the garden, but do this when the soil has started to warm up in spring. Allow around 20-30cm between seeds or plants once they are ready to go out after being hardened off. They tolerate a bit of overcrowding and look good in groups.
"The amaranths are very useful as they can be used as spot plants, as a foil for other plants and they are edible too. I know that they are a great favourite with florists because they can be used fresh or dry. The tassels of A. caudatus must look amazing in a bouquet."
Species and varieties
A. caudatus is also known as love-lies-bleeding because of its drooping, tassel-like racemes of tiny crimson red flowers that are produced in summer and hold into autumn. It is a bushy, erect annual with large ovate leaves that may need a little support because it is top-heavy. Height: 1.5m. Spread: 1m.
A. caudatus ‘Viridis’ is a form that features long tassels of pale, fresh acid-green flowers. A great cut flower. Height: 1m.
A. cruentus ‘Autumn Palette’ produces tall, feathery spikes of flowers in earthy colours such as rust red, orange, brown and cream, in summer and autumn. Height: 90cm-1.2m.
A. cruentus ‘Golden Giant’ is a substantial plant with prolific arching golden-brown flower spikes in summer and autumn. Produces plenty of white "grains". Height: 2.5m. Spread: 1m.
A. cruentus ‘oeschberg’ (syn. A. paniculatus ‘oeschberg’) is a ?many-branched but upright annual, with dark-purplish foliage and showy blood-red spikes of flowers. Height: 90cm.
A. cruentus ‘Velvet Curtains’ is a tall plant that features upright plumes of flowers and foliage both in the same shade of rich, dark crimson. Height: 1.5m.
A. ‘Hopi Red Dye’ is a fully reddy/purple variety that retains its colour. Seeds spread around easily so it can become a bit of nuisance, but if kept within bounds it is a great tall filler for the border. Height: 1.2-1.5m.
A. hypochondriacus ‘Pygmy Torch’ is a compact annual with lance-shaped purply-green leaves and erect, deep-maroon inflorescences. Good for drying. Height: 45cm. Spread: 30cm.
A. hypochondriacus ‘Green Thumb’ is a bushy, upright-growing annual with large, oblong, purple leaves and erect, plume-like, bright-yellow/green inflorescences from summer to early autumn. Good for cutting or drying. Height: 60cm.
A. paniculatus ‘Marvel Bronze’ has an upright habit with crimson to dark-red flower spikes and leaves. Height and spread: 10-50cm.
A. paniculatus ‘Hot Bisquit’ is an upright annual with ovate mid-green leaves and coppery/orange flower spikes. Height: 1m. Spread: 50cm.
A. tricolor ‘Joseph’s Coat’ has yellow-to-scarlet and green foliage all on one plant. Produces short erect plumes of deep-red flowers. Height: 45-60cm.
Thank you to Floramedia, which supplied the images for this article from its photo library