Identifying Harmful Spruce Tree Diseases

A close up on a spruce tree.

A spruce tree is a beautiful evergreen, capable of growing and thriving in a wide variety of extreme weather and climate conditions. In addition to being one of the most popular Christmas tree types, spruces are hardy trees that require little to no care. They provide an excellent shade cover and a natural home for many animals. However, rust disease, canker disease, and other parasites and conditions may affect spruce trees in your area, causing blight to local spruces.

Common Spruce Tree Diseases

Two of the most common spruce tree diseases are rust disease and canker disease. Parasitic fungi cause both of these diseases, and both result in browning of the needles on the tree. In many cases, the disease may kill a significant portion of the tree, and many trees suffering from one of these diseases need to be removed or cut down.

Rust disease is caused by a fungus that attaches itself to the body of the tree and grows to the needles of the tree. The spores grow in orange masses on the needles and spread most readily in the summertime. Due to the complex life cycle and growth patterns of rust disease fungus, it typically does not affect every tree in an area. Rather, it is common to see splotches of orange on a hillside where rust disease is present.

Canker disease, also known as cytospora canker, is due to an infection of the tree branch, caused by a fungus. The canker cuts of the water and nutrient supply to the infected branch, which causes the branch to die. The needles on the branch turn orange and brown and begin to fall off.

Treating Rust Disease and Canker Disease

If spruce trees in your area have been afflicted with either rust disease or canker disease, prepare to treat the trees in your yard and home. While preventing these diseases from attacking your trees may be impossible, by acting quickly upon detection of one or both of these diseases, you provide your trees with the best chance of survival and full recovery.

Canker disease may be effectively managed by isolating and removing the dead branches and other affected areas of the tree. Look for the fungus spores situated around the canker area. Careful monitoring and pruning is the best remedy for this spruce tree disease.

Rust disease may be treated effectively with a fungicide treatment such as Bordeaux mix or chlorothalonil. When applied appropriately, these solutions act to kill the offending fungi without causing permanent damage to the tree itself. However, fungicides are powerful poisons that should be used carefully and according to all manufacturer instructions. Consult with a home improvement or yard care specialist before applying fungicides to any plants or trees in your yard.

If you suspect that your spruce trees may be suffering from either rust disease or canker disease, confirm your suspicions by having them examined by an expert. If one or both of these diseases has struck in your yard, act quickly to treat the affected trees before the diseases can spread.