Peruvian lilies, also known as Alstroemeria, are herbaceous perennial plants native to South America. They are commonly grown in the southern United States where winters are warm. Peruvian lilies cannot tolerate cold temperatures. Peruvian lilies are valued for their attractive flowers that bloom in late spring and early summer in colors of purple, red, pink, orange, yellow and white. Peruvian lily plants are hardy in zones 8 through 11, but they can be grown in containers in cooler climates.
Plant Peruvian lilies in early spring after all threat of frost has passed. Select a planting site with fertile, well-drained soil that receives at least 4 to 6 hours of direct sunlight and bright, indirect light for the remainder of the day.
Prepare the planting area by spreading a 2-inch layer of organic compost over the site. Incorporate the matter into the soil using a garden tiller. Plant Peruvian lilies 6 to 9 inches deep and 12 inches apart to allow adequate room for growth.
Water Peruvian lily plants thoroughly just after planting. Provide supplemental water any time the surface of the soil feels dry to the touch, usually about twice per week, to keep the soil moist at all times. Reduce watering to once per week during winter.
Feed Peruvian lilies twice per year, once in the spring and again in early summer. Apply a 6-6-6 NPK fertilizer or similar according to the manufacturer's instructions for the best results. Water plants before and after applying fertilizer to prevent root burn.
Prune Peruvian lilies after flowering by using pruning shears to cut back the stalks to within 3 or 4 inches of the ground. Allow the plant to remain without pruning if self-seeding is desired. If you prune the plant, its energy will go toward producing tuberous roots instead of seeds.