Common Diseases: Dwarf mistletoe

Biology

Dwarf mistletoe is a parasitic plant that grows on the branches or occasionally on the trunk of a host tree, such as Douglas-fir, true firs, larch, pine, and junipers. It is yellow-green, olive-green, or somewhat reddish in color and grows in clusters. The tree’s branches become swollen and spindle-shaped at the infection site and may develop witches’ brooms. Severe infestations can greatly reduce growth of the host tree, sometimes causing dieback or death. However, since dwarf mistletoe survival depends on the survival of the host plant, death of entire trees is fairly uncommon. Dwarf mistletoe spreads by seeds.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Remove mistletoe from host tree by pruning out witches’ brooms or hand-picking the parasite.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

None recommended.