By Judy Sedbrook, Colorado master gardenerSM, Colorado State University Cooperative Extension, Denver County.
Are you looking for a colorful, quick growing plant to serve as a backdrop to your sunny border garden? Plants in the amaranthus family thrive in the sun and poor soil, and grow quickly to the size of a small shrub. They are an old plant that has recently gained new popularity as an ornamental.
Amaranthus was a prized grain plant in the Aztec, Mayan and Incan cultures prior to the arrival of the Spanish conquistadors. The fact that it was often mixed with blood and used in pagan ceremonies led to its near extinction when the Americas were invaded by Christian cultures.
The nutritional properties of amaranths have recently been rediscovered around the world. In countries such as Greece, Africa, India, Pakistan, Nepal, Tibet and China, amaranths are used as edible greens, herbs, and grains. One of the largest areas of grain Amaranthus production is now in Nebraska.
Fortunately, the beauty of the amaranthus did not escape some Europeans and they cultivated it, not as an edible, but for its ornamental qualities. The resultant cultivars are both heat and drought tolerant.
Amaranths grow tall and bushy with heights ranging from 2 to 8 feet and make a beautiful back-of-the-border plant or temporary substitute for shrubbery.
Amaranths are easy to grow so long as they have full sun. They do well against a warm, southern wall and after established, will thrive in poor soil and tolerate dry conditions.
The leaves of the amaranth are oval, 2 to 4 inches long, starting out green or dark red and changing to bright yellow, orange or florescent pink at the tops. The foliage of all varieties is edible, highly nutritious and has been described as tasting like spinach.
Flowers grow on tassels, erect or drooping, and up to one foot or more in length. They range in color from bright red and maroon to a chartreuse green, and resemble heavy chenille.
The red and maroon Amaranthus caudatus were popular in Victorian gardens and have an old-fashioned image. The green-flowered species look more modern.
The A. caudatus produces long-lasting flowers in erect or drooping tassels. One tassel may last for eight weeks before fading. It is available in shades of red, maroon, and chartreuse green.
Clusters of these tassels will branch, providing a cascade of color. They grow best in sunny areas and tolerate some dryness.
The A. cruentus, golden giant, has gold-brown, pendulous tassels.
A. hypochondriacus, or prince's feather, has leaves of purple, red or green. The tips of its stems are crowned with large erect spikes of tiny bright red flowers.
The A.tricolor, Joseph's Coat or Summer Poinsettia, is an edible vegetable commonly known as Chinese Spinach. This plant will grow from 3 to 6 feet, but is usually cut back to encourage branching and delay flowering. The flowers are insignificant and the plant is better known for its colorful, richly variegated foliage.
Amaranth is easily grown from seed. Seeds should be started indoors at a 70- to 75-degree temperature, 6 to 8 weeks before it's safe to plant outside. Start them in 3-inch pots. Amaranths are difficult to transplant except when the seedlings are very small.
In late May or early June, after all danger of frost is past, they may be planted outside. Plant 18 to 20 inches apart, in well-drained soil and full sun.
Seeds may also be sown directly outside, on the soil surface, as soon as the soil warms up in late May or early June. They will germinate in about 10-15 days.
The first flowers start forming in June while the plants are still small and will bloom from July until frost. They make good cut flowers and are excellent for drying.
Photographs by Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010