Plant the bulbs approximately 8 cm (3 in) deep in light, fertile, well-drained soil. Space bulbs 5 to 8 cm (2 to 3 in) apart. Grow in full sun to partial shade where the soil remains moist during spring. Water lightly after planting, then keep the soil slightly moist during active growth. Allow the foliage to yellow naturally so the bulbs can replenish their energy reserves. Colonies gradually expand over the years.