Thank you! Your people were absolutely amazing! They were here and gone in about 45 min. I could not believe how efficient they were in that short amount of time. I was extremely impressed and very Thankful. Thank you very much! ”- Rob S.


The Arborist was clean & thorough in explanation. I wasn’t home when the crew was there but the clean-up was terrific. ”- Pam W.

Black Ooze…What’s Wrong With My Tree?

Just like your skin can be cut and the wounds can get infected, so can the bark of your trees. Improper pruning, poorly cut branches, wildlife damage or other environmental impact can cause bacteria to get past the protective bark, causing an infection. When trees have a bacterial infection, you’ll often see the tree go into a state of overall decline combined with open, oozing wounds.

Ptsslime Flux

One such bacterial infection is called Slime Flux. It looks and smells as yucky as it sounds! Slime Flux is caused by several different species of bacteria and possibly even some species of yeast. The different bacterias that infect the sap consume it as a food and deplete the oxygen in the heartwood, which then turns a darker color than the rest of the surrounding wood. This discoloration is called “Wetwood”. Once these anaerobic conditions are created in the wetwood, the bacteria begin to ferment the sap, producing methane gas and increasing the pH in the tree. The resulting pressure pushes the fermented sap, or “slime flux”, out of the tree in an oozing stream. Once it hits the air, it often develops a foul odor. The infected oozing sap can even kill other plants that are growing around the base of the infected tree.

Wetwood and slime flux can affect a variety of trees including ash, oak, elm, mulberry and more.

How does Slime Flux Affect Your Trees?

If the tree is strong and healthy, it can off fight off infections of slime flux without too much damage. No action may be needed depending on the overall health and condition of the tree. However, if a tree is already under stress from drought, heat or soil compaction, the disease can infect the sapwood, especially in younger trees. Once the sapwood is infected, the infection inhibits the transfer of nutrients and water, so you’ll see leaves begin to yellow, wilt and then entire branches may die back. At this stage the deadwood will need to be properly pruned out of the tree.

It’s sometimes thought that because the conditions created by the fermenting sap actually suppress fungal decay in tree wood, that wetwood and slime flux could help the infected tree. The slime flux also kills other things on the bark of the tree, such as lichens or other competing plant material under the canopy. But again, if the tree is already unhealthy or stressed due to other factors, then the overall health of the tree could be jeopardized by the bacterial infection.

What Can I Do About Slime Flux?

Unfortunately, there is no curative treatment. If you notice slime oozing from your tree and an unpleasant odor, call us immediately. What we will do is focus on care that can help the tree improve its overall health, vigor and immune system. Exposing the root flares at the base of the tree, putting the tree on a fertilization program, pruning out any deadwood and correcting poor pruning cuts are all activities that can help strengthen the tree.

The best way to avoid slime flux in our urban trees is to properly maintain them and protect them from damage. Feeding at the right times of year, proper watering, and over all maintenance will keep trees healthy, vigorous and able to fight off pests and disease. Avoiding wounds by properly pruning your trees will also keep slime flux at bay.

Could your tree be in danger? Call us to have a certified arborist assess your trees.

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