From cedars to Douglas firs, conifer trees can add a unique touch to your property. What's more, they stay green year-round, so they can add a bit of freshness even in the ice-cold winter. But conifer trees, regardless of their species, are also prone to a number of health ailments. One of the most concerning of these is a disease called annosus root rot, which is often deadly once it infects a tree. If you have conifers on your land, here is what you need to know about this serious disease.
What is annosus root rot?
Annosus root rot, like the majority of tree diseases, is caused by a fungus. In this case, a species of fungi called Fomes annosus is to blame. The fungus enters the tree through lesions on the trunk or exposed roots. Once inside, it begins replicating, taking over the tissues in the tree's roots and lower trunk and leading to rot. Annosus root rot can also be spread from tree to tree by connections between the root system. So if one tree in a stand becomes infected, the other trees typically start showing signs of infection before long, too.
Annosus root rot can affect most any species of conifer tree, though it is more common in white fir and various spruce species. It occurs throughout the eastern and midwestern United States, but is rarely seen to the west of the Rocky Mountains.
What are the signs of annosus root rot?
Often, one of the first signs of infection is the appearance of a tar-like resin leaking from a lesion near the base of the tree's trunk. This resin is the tree's effort to fight back against the fungus and flush it from its system. In rare cases, the tree may be successful in this endeavor, but the annosus root rot fungus is quite hardy and does usually go on to cause subsequent symptoms.
As the disease worsens, you may notice that sections of the trunk begin to feel soft and take on a rotten appearance. Brackets (which look like large mushrooms) may begin to protrude from the base of the trunk or from any roots that are exposed. Before long, the tree's needles will begin to yellow and wither as the infected tree is no longer able to transport nutrients and water up its trunk.
How can you protect your conifers from annosus root rot?
Since the fungi have to enter the tree trunk through a lesion, you can protect your trees by preventing harm to their trunks. Do not use a weed whacker so close to your tree that you may nick it. Similarly, mow in a wide circle around your tree, and be very careful not to hit the tree with a snowblower or other equipment.
Since the disease can spread from tree to tree through the roots, you also need to be careful if you have one conifer in a grove removed. If you leave the stump of the removed tree behind, the fungus can enter through this stump and then travel to other trees. So always have the conifer stump dug out or burned completely after having a tree removed.
What should you do if your tree develops annosus root rot?
Sadly, this disease is always deadly. If you leave the infected tree in place, you'll just be allowing the fungus to replicate, which will put other conifers in the area at risk. So contact a tree service company such as Pete & Ron's Tree Service, Inc. at the first sign of annosus root rot. They can confirm the diagnosis and then remove the tree—and stump—in a way that reduces the spread of annosus root rot to other conifers.