Things You'll Need
Soilless potting mix
Alstroemeria, also called Peruvian lily, is a wonderful cut flower and lasts up to two weeks in a vase. Though it is most often propagated through root division, with a good deal of patience it can be grown from seed. Alstroemeria seeds can be bought, or gathered from existing plants. Given enough time and the right temperature conditions to germinate, they can be sprouted indoors and then transplanted to the garden. They can also self-sow and spread to every corner of your yard.
Buy alstroemeria seed at your local garden center, or gather it from existing plants. To harvest seed, allow seed pods to form when flowers fade. Wait for them to turn brown and brittle, then gather them before they burst and broadcast the seed in your garden.
Soak alstroemeria seeds in hot tap water for at least 24 hours. As the hard shells absorb water and soften, they will sink to the bottom of the container. Fish them out with your fingers.
Fill flats with soilless potting medium, and moisten it well. Sow alstroemeria seeds directly on surface and cover with a thin layer of the same medium.
Keep at 65 degrees Fahrenheit for four weeks, then put in the refrigerator for another four weeks. Moisten the soil every few days, never allowing it to dry out completely. This process, called cold stratification, "tricks" the seed into thinking it's been through a winter. Remove the flats from the refrigerator and keep at 65 degrees Fahrenheit. They should sprout within 10 to 15 weeks.
Cultivate an area in your garden that gets full sun in the morning hours, using a shovel or spade. If soil does not drain well, amend it with equal parts peat and sand.
Plant alstroemeria seedlings when they are 4 inches tall and all danger of frost is past. Space 6 inches apart. Water generously after planting.
Alstroemeria will spread rapidly through root division. Chop a section of root out with a spade and replant with plenty of water.
Do not allow pets to chew on any part of alstroemeria -- it is extremely poisonous.