linden tree disease

Asked November 10, 2016, 4:06 PM EST

Can you identify this disease that has killed my linden tree? It started dropping leaves a couple seasons ago, then this spring, just didn't hardly leaf out at all and I have had to cut it down. All of the wood was riddled with these spots, greenish brown. I'd like to know if it is something that has a treatment in case other trees start to get it thanks! I voted to support Extention !!!

Lane County Oregon

3 Responses

Wow, interesting issue! A couple of questions for you to help narrow this down:
Did the spots have this discoloration right when you cut the trunk or did the dark color appear at a later time (I'm wondering if this is a surface mold)?
Did you notice any abnormal appearance (other than the leaf issue you mentioned)? Any mushrooms or other fungi present on the tree or nearby?
Did the tree experience any wounding or injuries (storm damage, lawnmower, construction in vicinity)?
Just from the photo, the spots look like the start of a wood decay fungus. These fungi tend to attack stressed, dying or dead trees. It may be that this tree was stressed in the extreme winter cold that the area experienced a few seasons ago (which was followed up by some stressful summer heat). That stress allows the decay fungi to get a foothold.
I'm happy to take a further look at the trunk pieces or additional photos. You can send an email to brooke.edmunds@oregonstate.edu or, if you live nearby, drop off a sample at the Extension office at 996 Jefferson St in Eugene.
Take care and thanks for using Ask An Expert!

Hi, thanks for the answer!

the discoloration was there right as I cut the tree, it was in ALL of the trunk in every single piece, the distribution was pretty throughout, not more in one side than the other. The tree had been pecked into in a circular pattern by a woodpecker, maybe a dozen small holes all around one area at about 6' off of the ground, only in one part of the tree and no sap running out of it at the holes, other than that no damage at all to roots or branches. I had pruned some branches, but they'd healed over. Maybe the rot got in at a pruning scar or at the woodpecker holes?

Tree was in fairly shallow clay soil, only maybe 2 or so down to a bedrock layer (Eugene Formation, compacted volcanic ash). I'd say it was watered OK, we have an identical tree about 20 feet away in a better imported soil that is so far doing good. There is a sprinkler system for both trees and the shrubs near them, and they are all surviving just fine now. We think it is a soil fungus of some kind, we have had other trees with problems that we have treated the soil with captan and it has seemed to help.

Anything else you can suggest with the above would be very appreciated, as it was a difficult task to remove the dying linden tree and it's stump and I'd sure like to not have to do it again! Do you suggest the captan treatment at all, and is there a dosage for a tree based on DBH caliper? We have a lot of other trees that we'd like to keep healthy as much as possible. Losing that linden was no fun, since they are such a bee friendly tree and we like to have lots of bees around when we can.

Wanted to let you know that I'm running this problem by the OSU plant pathologist so I can give you the best course of management action. I will respond via your email once I have some additional information to share.

The holes you describe could definitely be sapsucker (a type of woodpecker) injury. Compare the photos here to what you saw on your tree.

Be back in touch via email soon.