Seeds typically germinate late winter to early spring. Only a very small percent of seeds succeed in infecting new hosts. Highest germination and infection rates occur under high light intensity and relative humidity. The endophytic system can survive indefinitely within a host without producing aerial shoots. In some species, the endophytic system often develops right behind the apical meristem of the host, infecting new branches as they develop and causing systemic infections.
Dwarf mistletoes extract most of their carbohydrate requirements from host trees.
Highest shoot production occurs under low light intensities. Seeds disperse when birds ingest berries and expel the sticky viscin-covered seeds. Seeds do not require ingestion to germinate, nor do seeds survive ingestion by all species of birds. Shoots photosynthesize most of the carbohydrate requirement and have a high light requirement. In addition, seed germination requires light.