Culture
Annual. Easily grown in moist, average, well-drained soils in full sun to part shade. Appreciates some afternoon shade in hot summer climates. Start seed indoors 6-8 weeks before last frost date or purchase starter plants. Set out plants after last frost date. Space smaller varieties 8-12” apart and larger varieties to 18” apart. Seed may be harvested from garden plants for planting the following year or cuttings may be taken from favorite plants in late summer.
Noteworthy Characteristics
Genus name comes from the Greek word amarantos meaning unfading in reference to the long-lasting flowers of some species.
Specific epithet means three-colored.
Amaranthus tricolor, commonly called Joseph’s coat, is grown not for its flowers but for its beautifully colored foliage. It is an upright, bushy annual that typically grows to 2-4’ tall in the St. Louis area. Species plants feature ovate to elliptic, green to purple leaves (to 10” long). However a number of cultivars are available in commerce featuring leaves brilliantly blotched with various shades of yellow, red, pink and/or copper, with the upper plant leaves often contrasting in color from the lower ones. Green-leaved species plants are sometimes grown as a vegetable crop (spinach substitute). Species plants are also sometimes commonly called tampala, particularly when grown for culinary use. Tiny green to red flowers in 1” axillary spikes are insignificant. Those strains identified as vegetable amaranth are selected for their culinary attributes. Others, identified usually as Joseph’s-coat cultivars, have been selected for their colorful foliage.
Problems
Watch for aphids. Root rot may occur in poorly drained soils. Susceptible viruses, aster yellows and fungal leaf spot diseases. Plants grown in the ground may need staking or other support.
Uses
Beds or borders. Interesting edging along walks or paths. Containers.