Do something like this around the pecan tree
bench - around the plum tree? perhaps a swirl around each tree in back meeting to become a heart?
Tree Bench Designs That Literary Embrace Nature
Organic design bench from binome | Hauscapsule
Cool deck around tree for outdoor seating - definitely want to make this in the summer!
As a seat around one of our trees, I like it.
bench around a tree images | Circular Bench Around Tree Pic #22
Matthias Pliessnig curved wood bench