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Two questions about our maples, one mature and one young #851005

Asked September 23, 2023, 3:22 PM EDT

We are so worried about our tree. Our mature maple is getting these dark stained areas up the trunk, so far it seems to be on one side, the north side. It's a big mature tree. Our street was repaved last summer, new water mains, not sure if that was traumatic to our maple. Sending photo of the trunk, close up of one of the problem areas, and of the entire tree. So far, the leaves look ok. A note, there was a sister tree on the other side of the driveway that started to die last year, we believe it was a girdling root. We had to have it cut down and we surely don't want to lose this one. We see no bugs, no sap per se but it looks like the "wounds" or whatever they are are weeping a little. You can see in the close up photo. Also, we planted a new maple last fall where the cut down one was. It is now about 6 feet tall. Leaves sprouted from base to top but nothing seems to be branching out. Should we prune off the bottom leaves and if so, how much and how should we do that. We hope you can help us. We really, really don't want to lose our maple.

Wayne County Michigan

Expert Response

Hello,

From the pictures that you provided; it appears that your tree has a case of “Slime Flux”.

Although the symptoms are unsightly, little damage is done to the tree in most situations. Slime Flux is caused by bacteria that enters the tree via water uptake from the roots or through an old wound or injury. As the bacteria builds up, it oozes out and leaves a dark wet mark on the wood. I’ll include a fact sheet on the disorder below.

Currently there is no control or treatment for slime flux, as otherwise, healthy trees with this condition can live a normal life span. However, making sure that the affected tree receives good general care will go a long way. Thus, you might want to consider if the tree is experiencing stress from other areas, such as soil compaction and mechanical damage. Adding mulch will also help quite a bit, as it will assist with conserving moisture and keeping mowers away from the tree.

With regard to the newly planted maple tree there are various factors that can come to play. One of which is transplanting shock or post-planting stress. When a new tree is transplanted, it can take several years before it becomes established. However, there is one concern, in that you mention that, “we planted a new maple last fall where the cut down one was.”

Planting a new tree on the site of the former tree can prove problematic for several reasons. The last tree possibly stripped the sites soil of the essential nutrient that young trees depend on. Likewise, the sawdust left behind from the removal or stump grinding could also change the soil’s nutrient balance. Furthermore, if any of the old tree’s roots are still there, it might affect the growth of the new tree’s root system. So, the best plan now is to make sure that the tree is well watered, provide mulch and monitor. If it starts to show signs of decline, I recommend retaining the services of a certified arborist. I’ll provide a link to a directory for you below.

Also, it I think it would prove prudent to do a soil test in the root zone area of the newly planted tree to check the nutrient levels.

Tree Trunks with Wet Wood or Slime Flux | University of Maryland Extension (umd.edu)

Can I replant a new tree in the same spot after an old tree has been removed? | Horticulture and Home Pest News (iastate.edu)

Find an Arborist (treesaregood.org)

Home | MSU Soil Test

Thank you for your question!  Replied September 28, 2023, 12:43 AM EDT

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