Fungi Blues

Some find it beautiful and some find it ugly, but blue stain fungi can spell bad news for the trees in your yard.

How does my tree get blue stain fungi?
Mountain pine beetles* are carriers of blue stain fungi and will transmit the spores into their host tree upon entering. Once introduced, the fungi will begin to infect the sapwood and clog up the tree’s ability to move nutrients and water that are vital for its survival. The fungi will often block up resin production, the tree’s natural defense against insects, which lets the mountain pine beetle thrive. It will additionally serve as a food source for the growing mountain pine beetle larvae. Trees heavily infested with mountain pine beetle and blue stain fungi The combination of the beetle and the fungi will usually speed up the death of the host tree. Heavily infested trees can die within months of infection.

How do I know if my trees have blue stain fungi?
A good indicator of potential infection is finding signs of mountain pine beetle infestation. Large pitch tubes, dust remnants at the base of the tree, and needles turning from a healthy green to yellow to a fiery orange-red are all good indicators of an infestation. A tree with blue stain fungi has blue-green to blue-gray colored sapwood in wedge shapes throughout the trunk. Unfortunately, the only good way to find out if you actually have blue stain fungi is to cut wood from the tree trunk, which is usually done after the tree has already died from infestation.

What can I do to prevent blue stain fungi?
There are preventative treatments for mountain pine beetle that are completed in the spring, but it is hard to detect most mountain pine beetle infestations until it is already too late. Many trees will now show obvious signs of their presence until the beetles are well developed or have already emerged. The best way to prevent them is to be proactive about treatment, especially if there are large populations in your area. If you have any questions about your conifers or about your trees in general please feel free to give our ISA certified arborists a call. They can provide you with a free estimate to help defend against infections and keep your trees happy and healthy.

*For more information on mountain pine beetles, please visit our page dedicated to this topic via this link.