Why are the needles on my spruce turning brown and dropping?

Q: What’s wrong with my spruce? It’s off-color and the needles are turning brown and dropping.

A: First, ensure that your tree is a spruce, not another type of evergreens such as pine or fir. Each type of conifer has its own diseases and issues.

A spruce tree can be identified by:

• Radiating branches (they resemble a bristle brush) of sometimes swirling needles
• Cones at the top of trees that hang downward and are cylindrical and oblong in shape
• The shape of the tree is narrow and cone-shaped
• The needles are not flat; they’re 4-sided and are sharp at the end (Pro Tip – If you can roll a needle in your fingers, it is not flat)

Learn more about how to distinguish pine, spruce, and fir trees. 

Symptoms

If you’re certain your tree is a spruce, check if it’s showing any of these symptoms:

• Needles that look purple or brown – these will be the older needles, while newer needles at the branch tips stay green
• Dropping needles in late summer or fall
• Sections where there aren’t many needles and you can see through the tree
• Black bumps on the infected needles that can be seen with a magnifying glass
• Most of the damage appears in the lower part of the tree

Cause

If those symptoms describe what’s happening to your spruce tree, then it’s most likely infected with a common disease called rhizosphaera needle cast.

Rhizosphaera needle cast is a fungal disease where the tree is infected each spring, which is why it is considered chronic.

Treatment Options

Unfortunately, there is no treatment that “kills” the fungus and keeps it from coming back. However, there are sprays that keep the infection to a tolerable amount each year. After a few years of successful treatments, you may be able to stop treatment for a year or two before resuming treatment again.

To determine if your spruce tree is worth treating, consider:

• How important is the tree to your landscape?
• What is the current level of infection?
• Are there sentimental attachments to the tree?

If you’re not sure that the problem is rhizosphaera needle cast, give us a call at 989-893-0000. The tree care experts at Bay Landscaping can diagnose the problem and help with the proper treatment.

Contact Bay Landscaping to schedule a tree assessment today.

Additional Resources

• For more information on rhizosphaera needle cast, you can read this article from Michigan State University on spruce decline.
• There are some helpful tips about how to identify and manage this disease in this article on the University of Minnesota Extension’s website.