Most of our cultural associations with mistletoe are positive. We think of them as sweet little green plants tied up in red bows and hung on doorframes at Christmas time. Even the scientific name of one of the plant families they’re derived from, Santalaceae, makes us think of Santa Claus and Christmas parties. Even so, in nature, mistletoes are far less benign. You should be wary if you see them growing in your trees.
Impact of Mistletoe on Trees
You’ll typically find mistletoe growing in large, round clusters at the tops of trees—especially oak, elm, and hackberry trees in this region. They provide some benefits to the ecosystem by providing shelter and food for birds and insects. However, mistletoes are parasitic; they steal nutrients and water from their host. One or two clumps of mistletoe aren’t necessarily lethal. Still, they make a host tree more vulnerable to adverse environmental factors such extreme temperatures, drought, and disease.
The most common way to get rid of mistletoe is by pruning. However, removing mistletoe isn’t simply a matter of chopping down the clusters of leaves. When a mistletoe grows in a tree, it extends root-like structures called haustoria into the branches. Even if you remove the mistletoe itself, the haustoria will still be there. Typically, homeowners need to remove the infected branches starting from below the mistletoe. This requires some precision, so be sure to consult an arborist before pruning.
Ethephon, a chemical growth regulator, has been known to have some effect on mistletoe as well. This method can potentially go wrong if done incorrectly though, so here are some tips for how to get rid of mistletoe this way. Do the treatment in late spring, before the host tree has begun putting forth its leaves, but when the temperature is at least 65 degrees Fahrenheit. Although you want to cover the mistletoe thoroughly, avoid getting the ethephon on the tree itself. Also, keep in mind that mistletoe may still come back after this process.
Mistletoe is not a death sentence for a tree; very rarely will an infestation merit a tree’s removal. However, some instances make removal is the best option. For instance, if a tree is old or fragile, an infection is well advanced, or there’s a risk of a tree infecting other vulnerable trees nearby. Tree removal is dangerous and should only be performed by a professional. Our Austin tree removal services will tell you if removal is necessary and how to best go about it.