Sprekelia formosissima is the one usually grown for its showy flowers – and even it is not very common, especially in colder climates. This tender bulb, native to rocky hillsides of southern Mexico and Guatemala, is hardy only to zone 8 and higher. It is sometimes offered as Amaryllis formosissima.
When the leaves begin to die back it should not be watered and should remain dry while dormant. Watering should resume once new growth begins to show and during flowering.
Fertilize container-grown bulbs lightly only when growing. Before planting, prepare the area by mixing some organic fertilizer in the soil (half a pound of fertilizer is enough for an area of 25 sq. feet).
Grow in well-drained, moderately fertile soil in a sheltered, sunny site. Protect in winter in cold areas.
Provide good air circulation, with temperatures between 65 (18 °C) to 75 F (23 °C) and nighttime temperatures between 50 t(10°C) to 60 F (15 °C).