Put the potted amaryllis in a cool (55 degrees F), dimly-lit place such as a cellar for 6-8 weeks. While a single bulb can produce several huge flowers, you can maximize the show by planting three bulbs of the same variety in one pot, or mix and match a few different varieties. google_ad_format = "300x250_as"; The large, rounded brown bulbs produce smaller bulbs over time to form a large clump of plants. This is not an exact science, so allow a week or two on either side for error. google_color_border = "FFFFFF"; After your amaryllis has rested for 2 to 5 months, you can start again. //-->. Water â¦ It was planted and bloomed. Likewise, how long does an amaryllis bulb need to be dormant? Dormancy If the bulbs are not rotting, they did not freeze, which is good. Let the plants google_color_bg = "FFFFFF"; Remove the bulb from its dormant storage six to eight weeks before you want flowering to begin. Water once and move the pot into a bright, 60-65°F room. plants over winter.