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Extension > Local Extension Offices > Meeker > County Agriculture Educator > Articles > Determining What’s Wrong with your Spruce Tree

Determining What’s Wrong with your Spruce Tree

Source: Sarah Eggert, Meeker County Extension Intern & Karen Johnson, Extension Educator – McLeod & Meeker Counties

Within the last couple of weeks, the Extension office has received a few calls regarding Evergreen issues, especially Spruce tree problems. Most diseases of spruce trees are started by fungus, but there are few that can be caused by bacterial or viral issues. Spruce trees can live years without any diseases or any needle problems. In fact, most fungi don’t develop in younger trees, but tend to develop in trees that are 10 years or older. Most evergreens are susceptible to diseases when they are put through stress, which can be caused by weather changes, or just by the environment in which the tree lives.

When looking for diseases within your spruce trees, there are a few things to determine before pinpointing what is exactly wrong with your tree. These diseases can range from needle issues, branch problems, or even the root of the evergreen. Determining where exactly the disease is on the tree can give you a clearer understanding of what is wrong with your spruce.

When looking at needle loss on your evergreen, it is important to note that once needles on the tree have fallen off, they do not grow back. The most common needle issue for most spruces in the Minnesota area is Rhizosphaera needle cast. According to an article on Diseases in Spruce Trees found on the Extension website, Colorado Blue Spruce is highly susceptible to this disease. It is also mentioned that trees that are stressed from drought, poor planting practices, or other factors are more likely to suffer from Rhizosphaera needle cast. We have seen a few of this type of diseases due to this fungus, and there are a few management solutions, depending on the severity of the disease.

If you notice that it’s more of the branch that seems to be suffering from something rather than the actual needles, the evergreen tree may be suffering from Cytospora canker, a fungus that affects the branches of the tree. This again is often found in Colorado Blue Spruce. This fungus is typically started by the fungus attaching to a wound or stress caused by an insect, and spreads throughout the branch. This can be prevented by reducing the amount of stress on the tree by watering often during times of drought. It is also important to prune and destroy any infected branches during dry weather. This will help the fungus from spreading onto the entire tree.

Finally, the last area to look when identifying the problem with your evergreen, would be to notice the shape of the tree. If you’re noticing reduced growth and thinning canopies, there might be a root problem within your tree. The most common root disease that affects spruce trees is Tomentosus root rot. Although this is a more difficult disease issue to identify, there are a few signs that can be identified without looking directly at the root. Spruce trees that are infected with this type of fungus are very prone to break or lodge during storms. You may also notice that mushrooms that are velvety brown on top and porous and buff colored below begin to appear around the base of the tree in the late summer. These few signs show that your evergreen may be infected with a root disease.

If you notice any of these symptoms in your spruce tree, the University of Minnesota Plant Disease Clinic is available to help! The University of Minnesota Plant Disease Clinic provides testing for a number of plant health conditions for a small fee. Further information about available services can be found on their website, at https://z.umn.edu/samplesubmission. Upon completion of testing, an expert will provide a diagnosis for your tree with recommendations on what to do about the disease or problem.

For more information regarding diseases in your evergreen trees, visit https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/spruce-tree-diseases/.
Good care and maintenance is important for the overall health of your trees. Remember, reducing the amount of stress on your trees will help reduce the chances of fungal disease issues.

Resources:
Grabowski, Michelle, and Cynthia Ash Kanner. “Diseases of Spruce Trees in Minnesota.” University of Minnesota Extension. Regents of the University of Minnesota, n.d. Web. 5 June 2017.

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