Cavity in King Crimson Maple

[John I.L.]

A King Crimson Maple in my yard has a carpenter ant infestation within a cavity in the main trunk. Arborist has recommended treatment of the cavity with Astro to manage the ants and then sealing the cavity with foam.

I am reluctant to have the cavity sealed as the tree seems to be compromised by more than just the carpenter ants. The cavity oozes black slime (odorless), weeping down the trunk and discoloring it. What do I do? Where do I begin? Could this be slime flux or some sort of canker? Who can diagnose the problem for me? In the meantime, is there anything I myself can do? Should I remove the slimy gunk from inside the cavity and spray for the ants?

The tree is right next to the driveway and close enough to cause damage to structures if it falls in severe weather. Also, I am not comfortable having a carpenter ant infestation so close to the house.

Thank you in advance for any advice and help!

 

[PJM]

Probably slime flux (bacterial wetwood) but there is no real treatment for it. You should have the tree evaluated for risk by a qualified arborist. Not recommended to seal the hole as this will not prevent reestablishment of carpenter ants. Treatment for the ants is advisable if you are concerned about them moving into your home. These treatments will likely need to be repeated every year or so.

 

[Oldmaple]

Yes, it has bacterial wetwood, not a health concern for the tree. Cavity is from fungal decay pathogens, the ants are secondary (they are mining out the already decayed wood). Treatments to kill the ants are only necessary if you are having problems elsewhere with them. Filling the cavity will allow the opening to close over sooner but does not keep the ants out or stop the decay. My concern is structural, how much decay is there and is the tree safe. How weak, how much top load is there, and what targets are there if it should fail.

 

[John I.L.]

Thank you, PJM and Oldmaple for your spot-on advice. Several certified arborists confirmed what you said. The tree is not hazardous and leaving it be seems to be the best option for now. We will have it re-evaluated next summer.