Hello Louis,

I've consulted with a colleague, Ryan Pankau, that specializes in tree and forest management.  He shared the excerpt below.  
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I'd recommend wrapping it during winter and waiting to see how it calluses over. Hopefully the tree will mount a good response and grow over this wound. It should be young and vigorous and able to bounce back. Good to see its being mulched but watering during dry times will help its recovery. Also, I advise to watch the crack for oozing, dark colored discharge. The area near the ground in the third pic shows a hint of that. The discharge is caused by slime flux (AKA wetwood). There is no real cure but it would be a sign of declining health. I've seen both young and mature trees develop wetwood and grow out of it if they can callus over quick enough. So, again, my hope is that its young enough and vigorous enough to grow through this. Other than wrapping this winter, there is no real immediate action that will help other than keeping it watered in late summer or other droughty times.
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He did also emphasize that the trunk should only be wrapped in the winter, as it can cause more problems with disease and insects if done in the summer.  

I hope this helps.  Please let me know if you have any follow-up questions.


Talon Becker
Illinois Extension

Lou,

I've consulted again with Ryan on this.  He said he generally doesn't recommend fertilizing trees in shrubs in most of IL, unless a soil test shows you are deficient in certain nutrients.  Trees and shrubs don't tend to have as much nutrient demand as your common food crops, such as tomatoes, sweet corn, etc.  So, if there is already plenty of a given nutrient in the soil to fulfill the tree's demand, adding more won't necessarily help anything.  He said proper pH and drainage are more important for trees, which helps to ensure that the nutrients in the soil can actually be taken up by plant roots.  

As for the insecticide, he said it wouldn't hurt the tree, per se, but he's not sure it would be a help either.  In his experience, he's seen insects attracted to wetwood, but not necessarily any species that would cause the tree harm.  And by applying an insecticide, it is possible you may kill off beneficial predator insects that help keep populations of various pest insects down.  

So, I'd say I wouldn't necessarily treat the tree preemptively with an insecticide.  Just keep an eye on it, and if you see an infestation arising, that would be the time to treat.  


Regards,
Talon Becker
Illinois Extension