The delicately colored Philadelphia Amaryllis flower will thrill your neighbors and friends. The Philadelphia Amaryllis is beautiful and is perfectly adapted for container growing inside the house. The Philadelphia Amaryllis is an interesting subject as a cut flower. A clump of bulbs will produce several stems of blossoms. As a containerized plant the Philadelphia Double Amaryllis will flower in about three weeks after the precooled bulb is planted and exposed to high illumination and warm temperatures.