Amaryllis (Amaryllis, Hippeastrum)

Amaryllis with their large, colorful trumpet-shaped flowers is a particular favorite of many gardeners. They are members of Amaryllidacae family, but there is some confusion between the genus Amaryllis and Hippeastrum, which are often referred to as amaryllis.

Botany

At one time, a large number of bulbous plants were classified as different species of Amaryllis. However, these plants have since been distributed among a dozen genera, and the belladonna lily (Amaryllis belladonna) is the sole species left in the genus Amaryllis. The belladonna lily bears clusters of fragrant flowers about 3 inches in diameter and pink, rosy red, mauve or white in color, usually with contrasting yellow throats. Flowers are borne on leafless 2-foot flower stalks in late summer or early fall and remain in bloom for 6 to 8 weeks. After flowers die, strap-like leaves emerge and remain until summer.
The large-flowered, brightly colored species and their many named hybrids which are commonly called amaryllis belong to the genus Hippeastrum. As with many plants that have been subjected to intensive breeding the origin of most hybrids is now obscure.
The Hippeastrum species and their hybrids produce 8- to 12-inch diameter blooms on each leafless, hollow flower stalk in springtime. Flower stalks grow 2 to 3 feet tall and may bear as many as 6 blossoms, though 4 is more common. Large bulbs may produce a second or third flower stalk about the time the flowers on the first or second stalk begin to fade. Cultivars (cultivated varieties) with single tiered or double flowers are available in bold colors which include fire-engine red, bubble-gum pink, and sunset orange. Some cultivars produce blooms in more subdued shades of pink, rose and salmon as well as pure white. Still others are spectacularly multi-colored. Strap-shaped leaves 1 1/2 inches wide and 18 inches long persist much of the year in Florida, but become reduced in the late summer, and are frequently killed by frost in northern counties. Hippeastrums are available from North America, Holland and South Africa. Dutch hybrids have the largest flowers.

General care

If healthy and beautiful blooms are desired, continuing care must be given. Weeds can be controlled by spreading a 2-inch layer of mulch over the bed at planting time. Seeds that do grow through the mulch should be removed before they become firmly established in the bed.
General care includes fertilization 2 to 3 times during the growing season with a special bulb fertilizer or 1 pound of 6-6-6 or an equivalent amount of other complete fertilizers per 100 square feet of bed.
Water is crucial for amaryllis growth. It is important that the soil is kept moderately moist during times of growth and flowering. Frequency of watering will depend greatly on soil type, time of year and weather conditions. A good cultural practice is to remove dead blooms before seeds are produced. Flowering in the following season will be reduced considerably if seeds are allowed to set. Removing dead blooms also helps to maintain the aesthetic value of the planting and may prevent disease problems. Life of blooms may be prolonged by removing anthers thereby preventing pollination and subsequently seed set. Anthers are male plant organs that are recognizable as long yellow filaments sticking out from within the flower.

Growing Amaryllis in Containers

Amaryllis can be grown very successfully in containers indoors or in greenhouses.
Amaryllis can be grown in clay, plastic or ceramic pots in media which will provide significant weight so they will not tip over when the stalks get tall and heavy with bloom. The pot should have drainage holes and be large enough to allow 2 inches of space between the bulb and the sides of the pot. Cover the drainage holes with pebbles or pieces of broken clay pottery and fill the pot with several inches of potting medium. Center the bulb in the container and firm the medium around the roots and bulb base. Continue adding and firming the medium until one-half of the bulb is covered. Leave the remaining one-half of the bulb exposed. Water the potting medium thoroughly and place the container in a cool bright location. No further watering should be necessary until the bulb begins to sprout.
Amaryllis can be forced into flower 6 to 8 weeks after planting. When signs of growth appear, move the container to a location where it will receive several hours of direct sunlight and increase the temperature to 75 degrees F. At this point, the soil should be kept consistently moist but not overwatered. Once the flowers have blossomed, remove the plant from the bright sunlight to keep the flowers fresh and prolong their life. Removing the anthers as soon as they are visible in the flowers may extend the life of the flowers further. Anthers are lobed, oblong appendages at the top of thin stalks (filaments) which produce the pollen grains. This procedure alters the appearance of the flowers, which some people find objectionable. The flowers will open in succession and each will last about 2 weeks.
When the flowers have faded, place the plant in light shade and water and fertilize to encourage the growth of new leaves. Bulbs can be left in their original containers for 2 or more years before repotting will be necessary.

Propagation

Amaryllis can be propagated by either seed, offsets or cuttage. Since seeds do not always produce plants similar to their parents, most named hybrids and selected strains are propagated by cuttage.
Seed pods of amaryllis develop rapidly and are mature within 4 to 5 weeks after the flower has been pollinated. Pods should be picked as soon as they turn yellow and begin to break open. Seed should be removed from the pod, allowed to dry for a few days and planted immediately in flats or beds in a well-drained soil. The seed area always should be partially shaded. Uniform and constant moisture and good aeration aid in increasing germination, hence soggy soil and poorly drained soil should be avoided. Coarse sand, vermiculite or charcoal may be added to the soil to improve drainage. The amount of light should be increased following germination until the plants are receiving full sunlight -- more sunlight means more food for storage in the bulb. The seedlings should be ready for spacing out in nursery rows a year after planting.
The bulbs may be cut vertically into as many as 60 pieces. Make sure that each piece has a portion of the stem tissue or basal plate of the bulb attached to the scales. The best time for the cuttage is from July to November, after the bulbs have made their full growth following flower production. Bulbs cut in the spring, immediately after flowering, usually give poor results as propagating material. The wedges should be dusted with a fungicide to retard diseases and planted immediately in a mixture of peat and sand or other porous, reasonably sterile media in flats or in a bed.
In a warm, humid atmosphere, small bulblets will begin to form between the scales of cut pieces in about 3 to 4 weeks. These will usually be ready for potting or planting after one growing season. New bulbs will bloom within 2 or 3 years, although it may take as many as 5 years for them to reach the flower stage in cooler regions.
After the tops stop growing and the leaves are turning yellow or brown -- in late September and October -- dig the bulbs and remove the offsets. You can then set out young offsets in rows or beds. In general, 2 to 3 years are required before these offsets will attain flowering size.

Disease and pests

Disease

Diseases are usually not a serious problem in growing amaryllis. There are a few diseases that may occur, however. One of these diseases is referred to as "red-blotch" or leaf scorch. It appears worse in areas of morning shade or where sprinklers hit amaryllis plants on a reoccuring basis. It is caused by the fungus Stagonospora curtisii. Red spots form on leaves, flower stems, and on the flower petals. On the foliage the spots are bright red to purplish, small at first but often increasing to form large longitudinal blotches with definite margins. Leaves and flower stems attacked by this fungus are characteristically deformed or bent at the point of attack. The flower stalks of heavily infested plants may break over at an infected area or wither and dry up before the flowers are produced. Dark reddish brown spots occur on the bulbs. The spots may develop into large rotted areas. The fungus and spores of red blotch are carried on the bulbs. Consequently, the leaves and flower stalks which push up from infected bulbs may become infected. Badly infected bulbs should be destroyed.
Amaryllis are subject to red spotting from various physiological causes, from injury and from mite and insect damage. This is not to be confused with the red blotch disease. Reddening from these causes appears as streaks, specks, or irregular patterns lacking definite margins or outlines.
"Mosaic" is a virus disease of amaryllis. The leaves at first have an indefinite yellow mottling which later becomes more pronounced, showing small angular spots or streaks of yellow and dark green color. Red streaks may appear on infected plants from secondary causes. The plants become more stunted each year. If the plants bloom, the leaves, flower stalks, and flowers are greatly reduced in size. The flowers that open are normally deformed. Since this is a systemic disease and there is no known control, it is advisable to destroy all infected bulbs and plants.
Seedling plants of amaryllis may be attacked by one or more fungi, such as Pythium spp. or Sclerotium rolfsii, that cause root and bulb rots. The attacks of this and other root-rotting fungi are confined primarily to seedlings in which they cause rotting of the bulbs or sloughing of the plant roots. Plants that have been attacked become pale, grow poorly, wilt, and eventually die. Succulent stems may have a black, sunken lesion at the ground line and the plants may rot off and fall over.
These diseases cannot be cured once they have become established, but they can be largely prevented by starting the seed, small bulbs, or bulb sections in soil where disease problems have not occurred or in soil that has been sterilized. Wetting pots, flats, or seedbeds with a solution of a good fungicide will help keep these diseases in check.

Pests

Insects directly damage amaryllis plants and allow disease organisms into plant tissue. Chewing insects, such as caterpillars and grasshoppers, should be carefully monitored and controlled by handpicking. Pesticides should only be used when the infestation can't be controlled manually.
Aphids are soft-bodied, sucking insects varying in size from 1/25 to 1/8 inch (1 to 3 mm) in length. Aphids suck plant fluids and cause new growth to curl and become distorted. The most serious result of aphid infestation, however, may be the spread of virus diseases.
Spider mites are tiny animals (1/50 inch or 0.5 mm long) that cause injury similar to that of sucking insects as they feed on the leaves of amaryllis during warm, dry periods. Bulb mites attack rotting bulbs and tunnel into healthy bulbs, transmitting organisms that produce bulb rot. Bulb mites are particularly damaging to bulbs of amaryllis.
Mealybugs are soft-bodied insects covered with a white, waxy material. When mature, they vary from 1/50 to 1/3 inch (0.5 to 8.5 mm) in length. They damage plant foliage by sucking plant fluids and may invade stored bulbs. Some control can be obtained by frequent syringing with a hose.