When you think of pests that can affect your trees, you probably don't think of other plants. Instead, you probably think of insects like ants or termites. You may even think of borers and other beetles. Or, if you have young trees, you may even worry about deer that could strip the bark and stunt the trees'growth.
That being said, trees do face risks from other plants, such as those included in the list below. These parasitic plants don't just steal nutrients from the soil around your trees. These parasites siphon vitamins and minerals from the trees themselves.
1. The Tangled Hair of Dodder
What to Look For
The most common dodder species in North America are salt marsh, golden, and California. They grow in long vines, but they don't often grow leaves. They might appear as a snarl of bare, yellowish branches on your trees, somewhat like woody hair. Some species have small flowers, but don't use the flowers as a deciding factor. If vines that look like unkempt hair cover your trees, then you have dodder.
How Dodder Affects Your Trees
Dodder can't use sunlight and soil to make its own nutrients, so it has to rely on other plants-a fact which makes dodder a true parasite. Dodder grows into your trees using root-like structures and snatches vitamins from the hosts' vascular systems.
Your trees need those vitamins and minerals to grow healthily and fight off diseases. So, if the dodder gets those nutrients instead, your trees will weaken and eventually die. Dodder will continue to devour nutrients from your trees until it kills them and spreads to other plants in your garden.
How to Treat Dodder Infestations
Dodder is aggressive, so you will probably need a professional arborist to eliminate it from your trees. However, you can do some management yourself. Pull the dodder before it starts to seed, or cover your trees with protective plastic until you've removed the seeds from your yard. Remember to punch small holes in your plastic so your trees don't overheat.
2. The Festive Cheer of Mistletoe
What to Look For
In North America, you'll usually find dwarf mistletoe, but you could have any of a large number of mistletoe species in your yard. However, most mistletoe species do resemble those sprigs of spiky leaves and bright berries that you see in winter holiday celebrations. The vines on mistletoe also have large seed nodules and a root-like texture that will spiral up your tree.
Essentially, if your tree starts to have leaves and berries that do not match its species, then you likely have mistletoe growing in your yard.
How Mistletoe Affects Your Trees
Mistletoe and dodder have a similar effect on their hosts. Mistletoe is also a true parasite in that it uses root-like structures to grow into your trees'vascular systems. This pest then weakens its hosts, but does not necessarily kill them-at least not by itself. Mistletoe's vampirism of host trees leaves those trees more vulnerable to disease and insect pests.
How to Treat Mistletoe Infestations
As with dodder, you need to act fast to make sure mistletoe seeds don't spread. Unfortunately, you can't just pluck mistletoe out of your trees. You'll have to prune the affected areas to not only save the infested trees, but the healthy trees as well. Once mistletoe takes root, that part of the tree will probably not recover.
That being said, arborists might have additional specialized treatments that they can use to free and heal your trees. Contact an arborist in your area to learn more.
Dodder and mistletoe represent only two parasitic plants that could threaten your trees' health. If you notice anything unusual growing on your trees, call your local experts for an evaluation.