In severe cases mistletoe will kill trees. The seeds of mistletoe are borne as white fruit on female plants. These berries are sticky and are spread by birds. The seed germinate and penetrate young, thin bark. As the seed germinate, a haustorium is formed which penetrates the cambium and eventually on into the wood.
Infection often causes large swellings to be formed around the point of entry.
Chemical control has not proven satisfactory, even though a large number of chemicals have been evaluated. Physical removal has been used but is only successful if the haustoria are removed. This may mean removing a large portion of the limbs in some trees. Cuts should be made 12 to 18 inches below the area where the mistletoe is attached. A hoe or rake have sometimes been used to brush the plants off the trees, but this gives only short term relief with new growth springing up from the point of attachment.