Mistletoe Tree Fungus

The ancient Celtic people believed mistletoe was a sacred plant.

Mistletoe has been part of European culture for thousands of years and has long been associated with Christmas traditions. Mistletoe is not a fungus, but a parasitic evergreen plant that weakens and kills host trees.

Identification

Mistletoe, which grows in tree branches, forms a rounded, brushy cluster approximately 2 to 3 feet in diameter. It has dense forked branches, thick, oval-shaped leaves and jointed stems. Male mistletoe plants produce pollen, while females produce sticky white berries between October and December. Mistletoe is poisonous if eaten.

Effects

Mistletoe produces a root that bores into the host tree's vascular system. The plant makes its own food, but it extracts water and nutrients from the host tree. Heavy mistletoe infestations can weaken or kill individual branches and reduce the vigor and growth in host trees. Mistletoe is most frequently found in oak, pecan and hickory, although other species are also susceptible to attack.

Prevention/Solution

Pruning out infected branches controls mistletoe infestations. Planting species that are resistant to mistletoe such as sycamore, cedar or crape myrtle will also prevent infections from occurring. Mistletoe growth is controlled through the use of plant growth regulators such as ethephon.

References

• University of Florida IFAS Extension: Mistletoe
• University of California Statewide Integrated Pest Management Program: Mistletoe
• University of Florida IFAS Extension: Florida Forest Health - Mistletoe