Dodder produces true seed; the seed germinates and produces a strand that searches for a host plant to parasitize. When in contact with a host plant, the dodder strand coils around the host's stem or leaf and forms specialized organs, called haustoria, at points of contact with the host. For the dodder to parasitize its host, the haustoria penetrate the tissues of the plant host and connect with the host's vascular tissue.

Phytoplasmas and some plant-infecting viruses may be transmitted from an infected plant to a healthy plant through dodder. Experimental transmission of a phytoplasma from an infected plant to a healthy plant of the same or different species can be accomplished in the laboratory or greenhouse; in such a case, a strand of dodder is placed with one end on or around the infected plant's stem, and the other end is placed around a healthy plant's stem - the dodder must parasitize both the donor (infected) plant and the recipient (healthy) plant.

Phytoplasma cells that are present in the host's phloem enter the dodder plant through the haustoria, multiply within and pass through the dodder strand, and eventually arrive at haustoria that have penetrated the healthy plant. The phytoplasma cells pass from the dodder into the recipient plant's phloem, completing the transmission.