Hi and thanks for contacting Ask Extension. From your pictures it looks like this is a blue spruce. It is definitely declining with age. Unfortunately this is fairly common for blue spruce trees unless they are planted in the ideal conditions. There are three principle types of diseases that affect blue spruce trees: needlecasts, tip blights and canker diseases. All of these diseases are caused by fungal pathogens and each produce specific symptoms that can be useful in diagnosing the problem. Needlecast: As the name implies, trees with needlecast diseases shed needles. Needlecast fungi often infect needles on the current year’s shoots. As the disease progresses, the needles die, usually the year following the infection. As a result, trees affected by needlecasts often have an outer “shell” of live needles on current shoots and dead needles on older shoots. Tip blights (usually affect pine trees so I don’t think this is your problem) and canker diseases. Canker diseases are caused by fungi that infect branches or the main stem of trees. Typical symptoms of cankers are sunken areas along a stem that may ooze resin. Trees may produce ridges of wound tissue around older canker infections as the tree attempts to restrict the fungus’ growth. As cankers develop, they can interfere with the branch’s ability to transport water and nutrients, resulting in the death of individual branches.

Numerous insect pests can impact spruces in Michigan, but the two most common are gall adelgids and spruce spider mites. In both cases, the insect pests are tiny and you may need a hand lens to see them. Often times, people are more likely to see the damage as opposed to the insect pests themselves.

Gall adelgids. Adelgids are small insects that feed on shoots by sucking plant sap. As they do so, they cause the shoots to deform and produce galls (swelling of a section of the branch) that resemble cones. Damage from gall adelgids is mainly aesthetic.

Spruce spider mites. Spruce spider mites cause needle discoloration and eventually kill needles, which can be mistaken for a needlecast disease. Technically, mites are not insects, but are related to spiders. This distinction is important since not all insecticides will control mites.

There are a number of factors contributing to the decline of blue spruce trees, including environmental changes, poor site conditions and new pathogens. Colorado blue spruce is native to arid regions in the Rocky Mountains. Michigan’s climate is generally more humid, especially in the summer, which is ideal for fungal pathogens to thrive. In landscapes, Colorado blue spruces have been planted on some sites that are marginal for their success. As a result, they are stressed and more susceptible to fungal pathogens. The ideal site for a blue spruce tree is full sun, good air movement and excellent soil drainage.

For some disease issues, such as needlecasts, fungicides may be effective in preventing or controlling the disease. It is important to note that fungicide treatments for needlecasts only protect new growth. For control to be fully successful, it may take two to three years of yearly fungicide applications. For canker diseases, the effectiveness of fungicides is usually limited. Removing affected branches is usually the best action to improve the tree’s appearance and slow the spread of disease within the tree.

For insect or mite issues, insecticides or miticides can be effective, however selection of the proper product and timing are critical.

As with any tree health problem, the first step in dealing with declining spruce trees is to diagnose the problem and identify the cause. From your pictures I cannot tell what exactly your problem is. The link below has some really good pictures of what these problems look like. If you want to know for sure I recommend sending an email to <personal data hidden>. Attach some pictures of the tree. Include some close ups and some from further away. They may ask you to send in some samples. Here is a link to the Plant and Pest Diagnostic Lab at Michigan State University. Plant & Pest Diagnostics Here you will find instructions on how to send in your sample and their fee structure. For large or important landscape trees, homeowners should contact a professional arborist or tree care company. Here is a link to find a local arborist. Enter you zip code on this website and it will bring up a list of certified arborists in your area. Find an Arborist

This is a link to the article that includes some good pictures.

https://www.canr.msu.edu/news/what_is_spruce_decline_and_what_should_you_do_about_it

If you decide to cut down your spruce and plant another type of evergreen, here is a link to a great article about some alternatives to blue spruce trees.

https://www.canr.msu.edu/resources/alternative-conifers-for-michigan-landscapes?utm_source=http://www.canr.msu.edu&utm_medium=referral&utm_campaign=canr-callouts