Spruce Tree oozing sticky substance.

(Question)

We have a couple of beautiful large spruce trees and they are oozing a very sticky off white/light brown substance on various parts of the trunk. Can you tell me what is causing this and if there is any we should be doing? They appear to be healthy trees except for this. We’d hate to lose them.
Thank you

(Answer)

Since the ice storm December 2013 in the Toronto area and southern Ontario, many trees have been stressed due to that, and the droughty conditions we’ve faced for the last number of years. Even though your trees are mature, watering them regularly during hot periods and right to freeze up, allows the trees to experience less stress due to weather. So, that is a first response to unhappy plants.

Your trees may look healthy from down on the ground, but it appears that a large branch has been removed nearer the ground, either by damage or cutting. A pathogen may have entered here. Oozing, whitish sap, which is what’s going on with your tree, is often a response to a pathogen. The likely pathogen is a fungus called Cytospora canker, especially if we see oozing sap (white substance) coming from areas of the base or limbs of the tree.

According to Stephanie Porter, the author of the following University of Illinois Extension article: “SOS: Help! My Spruce is Dying.” these cankered areas will girdle the tree at the base and cause branch death. When that happens, the newest needles usually die first. She says that Cytospora invades stressed trees and cannot be eradicated, once infection has occurred. She advises that management for this disease starts with pruning and destruction of infected branches. Disinfect your tools frequently, so that the fungus is not spread.

For further information about fungus and spruce trees: https://hyg.ipm.illinois.edu/article.php?id=264

This type of disease might be difficult to determine yourself. It is a good idea to call in a professional arborist, who can evaluate your trees for the disease or other pathogens, and advise you as to your next steps.