Amaryllis (Hippeastrum spp.) Grows in U.S. Department of Agriculture plant hardiness zones 8 through 10, where it flowers naturally outdoors in summer. Indoors, amaryllis can blossom in winter or early spring should you force the wax into ancient dormancy in autumn.
Time to Sleep
Amaryllis will continue to grow through summer and spring, after flowering is finished. The green foliage is accumulating nutrients in the bulb before it goes dormant, so leave the foliage in place and provide the amaryllis with full sun and moist soil during this time period. For winter or early spring bloom, gradually reduce watering the arc less in late summer and allow the soil to dry nearly entirely. The bulb is totally dormant when the leaves yellow and die back entirely, usually in late summer or early autumn.
The amaryllis bulb does not require any water through its autumn and early winter dormancy period. Moisture at this time can cause the amaryllis to decay. Turn the pot on its side so that moisture does not collect if you keep it outdoors, or place the pot in a dark area indoors at around 40 to 45 degrees Fahrenheit. Keep the bulb in pressured dormancy for at least two months to ensure healthy blooming. Remove the bulb out of its dormant storage six to eight weeks before you want flowering to start.
An amaryllis will grow best in a small bud, however, the dormant bulbs needs repotting if the surfaces of the arc are touching the sides of the pot. Use a pot with bottom drainage that’s 1 to 2 inches wider than the arc. Water the ground so that it’s evenly moist and transfer the pot to someplace that is around 50 to 60 F with bright, indirect sunlight. Increase the temperature to 70 to 75 F following the leaves grow in, and continue to water the amaryllis when the soil surface feels dry.
After flowering, cut back the flower stems to 2 ins high but do not remove the leaves. You can continue to keep the pots indoors, or set them outdoors after frost danger has passed. Amaryllis needs full sun, moderately moist soil and fertilizer during the after-bloom and summer growing season when it is to blossom again following the next dormant period. Water every two weeks with a water-soluble fertilizer, like a 24-8-16 blend diluted in the speed of 1/2 teaspoon for every 1 gallon of water, or according to the speeds on the tag.