The large, luxurious blooms and thick stalks that rise from the long-lived amaryllis bulbs belie a delicate sensibility. Amaryllis bulbs are safe to overwinter in the ground at ambient temperatures between 45 and 75 degrees Fahrenheit. They can be left in the ground where soil temperature can remain warm or is mulched heavily. Beyond this natural range, amaryllis bulbs must be dug up and stored indoors over winter to survive and bloom the following spring.
Mulch over ground-planted amaryllis in the fall with 2 to 3 inches of straw, compost, shredded bark, leaf mold or cocoa bean hulls or another organic insulating material. Cover over the bulb, extending the mulch blanket to a square foot area around the bulb and roots.
Dig up your amaryllis in the fall for over-winter storage indoors in climates where the temperature drops below 45 degrees Fahrenheit. Carefully excavate up the bulb and roots, and gently brush off the planting soil to clean the bulb.
Place the bulb in clean, barely damp sand in a dim and cool location with temperatures between 45 and 55 degrees Fahrenheit until re-planting outdoors in spring when temperatures have climbed to above 60 degrees.
Moisten the sand lightly with water if needed to prevent the bulb from desiccating during storage.
Move your container-grown amaryllis plant to an indoor location in the fall in climates where temperatures drop below 45 degrees Fahrenheit.
Site the plant where it will receive bright indirect sunlight, ambient temperatures between 50 and 55 degrees and Fahrenheit for a period of eight to 10 weeks.
Water only lightly and refrain from feeding during this period.
Return the bulb to a warm location with temperatures between 65 and 75 degrees Fahrenheit after the cool period. Water the soil thoroughly with tepid water and feed with a balanced fertilizer formulation diluted with water to 50 percent of its recommended application strength.
About this Author
An omni-curious communications professional, Dena Kane has more than 17 years of experience writing and editing content for online publications, corporate communications, business clients, industry journals, as well as film and broadcast media. Kane studied political science at the University of California, San Diego.