Mistletoe hung in doorways is a traditional holiday decoration, but when it's growing on trees in the landscape, this parasitic plant may not seem quite as charming.

There are two types of mistletoe: broadleaf and dwarf. Broadleaf mistletoe is evergreen and can be found growing on common trees such as flowering pear, ash, and birch, while dwarf mistletoe attacks firs, pines, and other conifers.

Mistletoe robs trees of both water and nutrients. If you see small amounts of mistletoe growing on healthy trees in your landscape, it's probably not a cause for concern. However, if a tree is heavily infested, individual branches may be weakened or killed, and trees affected by drought or disease may be stunted or even...