WSU Extension


Armillaria root rot 
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California gallfly 
Jumping oak gall 
Leaf galls 
Oak leaf phylloxera 
Oak ribbed casemaker 
Oak treehoppers 
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Stem galls 
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Caption: Oak mistletoe (a true mistletoe)
Photo by: J.W. Pscheidt
Oak : Mistletoe
(revision date: 4/28/2014)

Mistletoe is a parasitic plant which grows on the branches of a host tree. True mistletoe, found on oaks and a few other hardwood species, does not grow on conifers. It is spread by seeds ingested by birds and carried to new hosts. True mistletoe is a perennial plant. Leaves are olive-green and leathery. Seeds are borne in white berries. Host tree branches often develop large swellings at the point of mistletoe attachment. Branches are weakened at the attachment point and often break in storms. Mistletoe is also an aesthetic problem, since the large growths can be unsightly. All parts of mistletoe are considered poisonous.
Management Options

Non-Chemical Management
  • Remove mistletoe by pruning out infected branches or hand-picking the parasite.
  • Heavily infested trees may be removed and replaced with non-host trees such as conifers.
  • Commonly affected oaks include white (Quercus garryana), black (Q. kelloggii), red (Q. rubra), scarlet (Q. coccinea), and pin (Q. palustris).
Select non-chemical management options as your first choice!

Chemical Management

None recommended


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Caption: Oak mistletoe (a true mistletoe)
Photo by: J.W. Pscheidt