Peruvian Lilies seem to prefer bright shade in Davis.
Peruvian Lilies (Alstroemeria pelegrina) are members of the Amaryllis (Amaryllidaceae) family and occur naturally in cool mountainous regions of Chile, Brazil and Peru. The genus is named after Claus Alstroemer, a pupil of the great botanical classifier Linnaeus who went to South America and sent back Alstroemeria seeds. These late spring blooming perennial flowers are like miniature lilies, with spotted or striped markings, shaded colour, or contrasting patches and attract bees, butterflies, and birds. The smooth light green leaves twist at their base so that the upper and lower surfaces are reversed and internally the anatomy has adapted to this reversed position; interestingly, Alstroemeria stems move rhythmically from side to side in a spiral motion as the plant produces new cells in a spiral sequence — you can sometimes see a spiral growth pattern on the stem. These hermaphroditic plants typically grow from two to three feet high and are frost tolerant.
Alstroemeria are sensitive to soil temperature and will put effort into producing more tuberous roots at the expense of flowering shoots when soil temperatures rise; because of this, Peruvian Lilies should be planted in partial or bright shade to ensure good flower production — container grown plants will heat up much more quickly than plants in open ground. Alstroemeria are fairly easy to cultivate in rich, well-drained soil in our local climate and, with few pests or diseases to inhibit growth, can quickly become invasive if not controlled by deep borders. Its tubers spread rapidly about one to two feet below the surface in finger-length roots. Propagation is by division, and the plant sap can cause contact dermatitis in some individuals.
Alstroemeria produce beautiful cut flowers that last about two weeks in water; because the leaves yellow long before the flower, it's recommended that leaves be removed before arranging.