The Genus Amaranthus
Family Amaranthaceae
The amaranth family is a large family that is spread around the world. Most are herbaceous plants but a few are shrubs, trees or vines. Important garden plants in this family include beet (Beta vulgaris,) spinach (Spinacia oleracea) and quinoa (Chenopodium quinoa.) Alternanthera, Amaranthus, Celosia, Gomphrena and Iresine are genera that include garden plants.
Amaranthus tricolor
Joseph’s coat
This is a summer annual that grows to three or six feet tall. Depending on the cultivar, the large leaves may be green with some reddish tint or brightly colored. Ornamental forms may have red, pink, orange and yellow colors in the foliage. The small flower clusters blend in with the foliage. Young leaves and tender new shoots may be eaten raw or cooked. This is one of the greens that is used to make callaloo in tropical America. Grow it in full sun, in a reasonably moist, well-drained soil. If you are growing it as a vegetable, it responds well to a little fertilizer or compost.
Plants are propagated by seeds. Seeds are available from local nurseries and seed catalogs.
Young plants of the cultivar, ‘Early Splendor’, have attractive burgundy foliage. As the plant approaches flowering size, the new leaves turn bright pink with orange/coral highlights in the youngest leaves. In my zone 9 garden, they were finished by early August.
other Amaranthus species
Amaranthus caudatus is also known as love-lies-bleeding. This is another garden species that is similar to A. tricolor in its size and cultivation requirements. Cultivated forms usually have green to burgundy foliage with showy, flower spikes that arch or droop from the tops of the stems. Flower spikes may be yellow-green, pink or red. Because of its long, conspicuous spikes, it is comparatively easy to collect the edible seeds of this species. Its stems tend to lean and may require staking. Photos of this plant are labeled on some websites as Amaranthus tricolor.
Several species of Amaranthus may be found in the Coastal Southeast. The common name, pigweed, is given to several because they thrive in the manure-rich soils around pig lots. Plants are native and introduced weeds. Reportedly, all of them have edible leaves and seeds but the leaves may contain high levels of nitrates if grown in nitrogen-rich soils.