Plant crinum bulbs in a full-sun location after the danger of frost has passed in your area.
Bury the bulb 4-6" deep, but make sure the neck of the bulb is visible. The neck of the bulb is the top portion where the leaves will come out from.
Crinums like moist growing conditions; be sure the soil they are planted in is rich in organic matter such as humus and compost.
Prior to sprouting, apply a liquid fertilizer on a regular basis to encourage blooms. Once the flower stalk appears, there is no need to continue fertilization.