Forest
Health Protection, Southern Region
MISTLETOE,
caused by Phoradendron spp.
Importance. - Many species of hardwood trees are affected by mistletoe, but oaks and hickories are most commonly attacked. Mistletoe is used in Christmas
greens and can be found throughout the South. The impact of infestation is not normally severe, but the parasite may lower individual branch vigor. Where
infestations are severe, tree decline may progress to the point where insect and fungus pests combine to kill trees.
Identifying the Parasite. - Perennial, broad-leafed, evergreen plants appear in the tree crown. Identification is easier in winter, when the host tree's leaves are
absent. The plant has opposite leaves and inconspicuous flowers that produce white to red berries in the fall.
Clusters of mistletoe. (Click for detail. JPG 43K)
Mistletoe plant. (Click for detail. JPG 46K)
Identifying the Injury. - The presence of the plant is the only reliable sign of an infestation.
Biology. - Seeds are animal- and bird- dispersed between and within tree crowns. A sticky substance on the seeds helps them adhere to susceptible young
branches. Upon germination, a peglike root penetrates to the tree's, vascular system, extracting water and needed nutrients.
Control. - Control is usually not necessary. If desired, tree branches may be pruned at least one foot back from the plant's attachment point, and then discarded.
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