I have a large, mature water oak growing in my yard that has me concerned. There is a large cavity in the trunk. I’m not sure if I should fill this up with something like concrete. Also ...

This is the same compound found in other poisonous plants like poison ivy and is responsible for causing a rash in most people. What does the poison oak rash look like A rash from poison oak will ...

They can be big, like trees, or small and colourful ... it means it's a deciduous tree. It has acorns too. I think it must be an oak tree. Look, it matches the picture on our sheet.