Amaryllis plants are desirable for their tall, slender stalks of large, trumpet-shaped flowers. These tropical plants, which are native to South Africa, can be grown indoors or out. In fact, they make excellent houseplants due to their long-lasting blooms. They are easy to grow, according to Iowa State University. Amaryllis plants are an excellent choice for the beginning or experienced home gardener.
The best amaryllis bulbs are large, firm and healthy. Container-grown amaryllis plants should be grown in a container that is only an inch larger in diameter than the bulb. This will cause the roots to become pot-bound, which is actually how these flowers grow best, according to the University of Illinois. Amaryllis bulbs thrive in rich, well-draining soil, whether planted indoors or outdoors. Plants grown outdoors will only grow well in a tropical or subtropical climate. They should be planted so that half of the bulb protrudes above the soil, and watered well directly after planting.
Indoor amaryllis plants do best when located in a warm, bright location where they will receive full sunlight. Outdoor plants will grow in light--but not heavy--shade. The temperatures in that location should remain around 75 degrees during the growing and flowering period, according to Iowa State University.
Water and Food
Amaryllis plants need soil that is barely moist. They grow best if the top layer of soil is allowed to dry out slightly between each watering. One watering per week should be enough, according to Iowa State University. These plants should not be fertilized until the leaves appear. At that point, they can be fertilized with a nitrogen-rich, water-soluble fertilizer. Fertilizing should be done once or twice a month according to the directions on the label for the size of your plant.
The foliage of outdoor amaryllis bulbs should be allowed to die down completely before removing it from the garden bed. This returns the plant's nutrients to the bulb to be stored for next year. Indoor plants that will be forced to re-bloom need to be moved to a dark and cool location (about 55 degrees Fahrenheit) once the leaves have died back. The plant should remain there for between six and eight weeks without water, according to the University of Illinois. After that time, the pot can be brought back out to a warm, bright area, and the home gardener can resume watering the amaryllis. Once watering resumes, the plant will grow and may bloom again during the winter months.
Insect pests can take up residence on amaryllis flowers. They do not usually threaten the life of the plant, and can be easily rinsed off with water. Some, such as the narcissus bulb fly, may lay eggs in the bulb before it is planted, according to the University of Minnesota. The only way to prevent this is to make sure your bulbs are healthy before planting them. In addition, the use of sterile potting soil will avoid fungal diseases that can infect and destroy the bulb.