Mistletoe is hugely important for wildlife, supporting it’s own assemblage of insects and offering an important food source for birds, but it is crucial to keep mistletoe in check within an orchard, particularly on older trees. Mistletoe is parasitic, taking nutrients from its host, so too much can affect the health and vigour of a tree. Being evergreen mistletoe can also have a significant ‘sail effect’, making trees much more vulnerable to winter storm damage.
The website www.mistletoe.org.uk, written by UK mistletoe expert Jonathan Briggs, is a fantastic source of information.
This short summary factsheet is also available to download: Mistletoe Factsheet.