I know that to some this might seem a bit bonkers, but all I can say is that if you sit with a tree, and let your mind go oh so quiet, you might just find that they can talk to you too.
I don't know how it is possible. My feeling is that perhaps it is via a connection you both have to the Great Whatever that allows your differences of being to be passed by and a pure soul connection to be made. At any rate, it works, and plenty of people other than me have done it too. It is so peaceful, and they are in general very wise beings. I guess standing around observing and thinking and not running like a loon everywhere might have something to do with that.