Just noticed this! A user has created a Community Tree Editor! Have not tried it yet myself because of need to get back to IRL!
From skimming through the thread, the tool gives you some control over density, species, and height. I like the comment of a forum member in perusing the thread, something like, “I’m from AZ … and as soon as I saw cactus, you had me!” 
Maybe Asobo will consider adopting good tools created by users and immortalize them by including them in the game credits if the tool invented really is a GREAT “game changer!” (pun intended). @ModeratorTeam