On my travels throughout Davis in support of the Davis Tree Commission, I see many examples of the negative effects of mistletoe on residential and city trees. The tree commissioners and those residents presenting a petition for tree removal do not request or vote to remove a tree without concern. The decline of legacy trees, which are some of the city’s most beautiful and recognized landmarks, is an example of the worst effects of mistletoe.
Currently, a costly and losing battle is being waged to save mature trees from the parasitic effects of mistletoe, notably the black walnuts on West Russell Boulevard. Mistletoe may have some advantages to wildlife in a natural forest environment, but the loss of habitat and shade from the mature trees attacked by this scourge in our urban forest far outweighs any benefits within the city. The forest of Davis is not a “natural environment,” but does provide a year-round lush and varied habitat for insects, birds and mammals.
When planting and replacing trees, the tree varieties approved by the city forester should be given priority. These trees are able to thrive in our local environment and are often mistletoe-resistant like my favorite variety, the valley oak.
On balance, mistletoe is not beneficial to the trees of our city’s neighborhoods because the varieties of exotic mature trees that support mistletoe cause great cost for upkeep and removal.