Walnut trees are tall and majestic, and they produce delicious nuts. If you're lucky enough to have one on your property, then it's important that you do all you can to keep it in good health. This includes knowing the basics about thousand cankers disease -- a serious disease that can infect walnuts -- and how to prevent and deal with it.

What is thousand cankers disease?

Like most tree diseases, thousand cankers disease is caused by a fungus. Walnut beetles carry the fungal spores from tree to tree, and once the spores reach the tree, they develop into adult fungi which form black cankers, or sores, on the tree's trunk or larger branches. Thousand cankers disease affects most species of walnut tree, though the Arizona walnut is thought to be resistant.

What are the signs of thousand cankers disease?

Often, a tree does not start showing signs of disease until the infection is pretty severe. Each time a beetle burrows into the tree's bark, a canker forms -- but if these cankers are higher up on the trunk or branches, they're easy to overlook at first. As the tree's bark and internal tissues become more extensively damaged, however, the tree's leaves begin to die. The leaves on entire branches wilt suddenly and then fall to the ground prematurely. At first, this may happen on just a few limbs, but within a year or two, large portions of the tree are affected.

What can you do if your tree has thousand cankers disease?

First, call a tree service to come inspect your tree and ensure it is not suffering from a less serious condition like anthracnose or leaf spot. Serious cases of these diseases can sometimes mimic the signs of thousand cankers disease. If your tree is found to have thousand cankers disease, sadly, the best thing you can do is to have it removed. It will die on its own within a few years anyways, and by having it removed, you'll be reducing the spread of the fungus to other trees in the area.

Can you protect a healthy walnut tree from thousand cankers disease?

There's nothing you can do to guarantee your tree won't become infected, but there are steps you can take to decrease the risk:

• Never bring other wood onto your property in case it is harboring walnut bark beetles.
• Keep your trees well pruned. Dead and decaying branches are more appealing to beetles.
• Only trim trees in the late winter. Recently trimmed branches are more appealing to the walnut bark beetles, and the beetles are less active in late winter.

For more information, talk to a professional like TimberMen Tree Service.

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