An amaryllis is a rewarding winter houseplant because, like paperwhite narcissus, it can go from dormant bulb to full bloom in a matter of weeks. But unlike paperwhites, which aren’t worth saving once they are done blooming, an amaryllis bulb is a long-term investment that will bloom every winter—if you know how to keep it happy.
It’s a common mistake to trim off the long, strappy leaves that emerge with the flower stalk. Those leaves are absolutely necessary; through photosynthesis, they capture the solar energy that goes toward next year’s flowers. After it’s done blooming, put the potted amaryllis in a sunny, warm window and water it regularly to encourage more leafy growth. Give it a bit of fish emulsion or other water-soluble fertilizer every other week. When the weather warms and nights remain consistently above 50°F, move the pot outdoors, letting the leaves acclimate to direct sunlight gradually. Continue feeding and watering to encourage lush growth; the leafier the better.
Around Labor Day, stop watering and feeding your amaryllis and let the bulb go dormant. Some gardeners turn the pot on its side to make sure the soil dries thoroughly. Once the leaves have shriveled, move the pot indoors and keep it dry for at least 10 weeks, or whenever you’re ready to awaken the bulb and begin the flowering cycle again. Top the soil with a half-inch or so of compost or fresh potting mix, water well, and stand back!