Alstroemeria can be started from seeds, rhizomes or container plants, with rhizomes being the preferred cause of an earlier bloom. Spring, after the last chance of frost is the optimal time to plants and garden; in milder climates it can also be planted in autumn. If you are planting rhizomes, position them five — six inches below the surface with the pointed side facing up quite well. Plants are relatively resistant to pests and diseases, but they can occasionally be affected by aphids, spider mites, and powdery mildew. Regular inspection and prompt treatment with insecticidal soap or neem oil can keep these issues in check.