Culture
Best growth in sandy, gritty, well-draining soil in full sun to part shade. Does not tolerate heavy, wet soils. Too much shade will cause the flowering stems to become leggy. This plant is known to be hardy to 10 F (Zone 8a). In colder weather they can be dug and stored in a cool, dark area indoors, similar to other tender tubers like dahlias, or they can be grown in a pot and brought inside a basement or garage. A layer of winter mulch can also increase hardiness. During the growing season, fertilize well and keep watered. May require staking. Where hardy, will self-sow freely and spread slowly by rhizomes.
Noteworthy Characteristics
Alstroemeria ligtu subsp. incarnata, commonly called inca lily, is a rhizomatous flowering perennial native to the foothills of the Andes in central Chile. In the St. Louis climate, this plant is not hardy and should be treated in a similar manner as dahlias. The flowering stems can grow up to 3 ft tall, with narrow lance shaped leaves along the stem. The flowers are tubular in shape with flared petals, pink to salmon colored with bright orange streaks, and are held at the ends of the stems in an umbel. An excellent cut flower.
Genus name honors Swedish botanist Klaus von Alstroemer (1736-1794) who was a student and friend of Carolus Linnaeus.
The specific epithet ligtu is the Chilean vernacular name for this species of Alstroemeria. The infraspecific epithet incarnata means flesh-colored.
The common name refers to the Inca people who live where this plant is native.
Problems
Poorly drained soils can cause root rot. Botrytis blight, a fungal infection of the leaves, can be problematic during warm, humid weather. Avoid watering the foliage and provide adequate spacing between plants to improve air circulation. May require staking.
Uses
Use in containers, alpine gardens, rock gardens, cutting gardens, or sunny borders with well-draining soil.