Amaryllis, a bulbous perennial valued for its ornamental flowers and ease of care, thrives in plant hardiness zones 7b through 11 only. Gardeners in cooler zones must cultivate the plant in containers. Amaryllis blooms during winter, producing flowers up to 8 inches in diameter in shades of pink, red, white or orange, depending on the variety. The most common varieties sold include Dutch and South African hybrids, which flower almost immediately after purchasing with no special care. Part of the plant's popularity stems from its blooming habit. Amaryllis adds color to the home during the drab winter months when most other flowers lay dormant.
Grow amaryllis in a container that is 1 to 2 inches wider than the width of the plant's bulb, and has drainage holes in the bottom. Provide a growing medium that consists of one part peat moss and one part perlite to provide adequate drainage and fertility for growth.
Form a small hole in the soil mix and place the bulb inside, pointed side up. Cover with soil, leaving the top third of the bulb still exposed. Keep in a location that receives at least four hours of bright light, such as a south-facing window.
Maintain a constant temperature of 70 to 75 degrees F at all times for optimal growth. Reduce the temperature to about 65 degrees F when flowering begins to prolong the life of the blossoms. Resume normal temperatures after flowering ends.
Water amaryllis immediately after planting, and about once every seven to 10 days thereafter to keep the soil consistently moist. Increase watering frequency when flowering begins, soaking the soil whenever it feels dry to the touch. Add water until moisture seeps from the drainage holes, and then pour away all excess.
Feed the plant twice a month during spring, summer and fall using a liquid houseplant fertilizer. Apply according to the manufacturer's directions for the best results. Never feed a plant that has no foliage.
Remove faded amaryllis blossoms as soon as possible to prevent seed formation. Keep the plant in a sunny window for two to three months after flowering has ended to promote future bulb development. Transfer to its original location after this time.
Repot the plant once every one to two years during late November to provide additional room for growth and a fresh growing medium. Increase the size of the container by about 1 inch. Water immediately after repotting to encourage growth.