My back yard is a land fill big chucks of concert, asphalt with a thin layer of topsoil. The land was raised up 14 feet due to flooding. There was ash trees all along the river bank they back filled around the trees. I had to cut them down due to ash bore. I now want trees back along the bank. But dont know how to plant new trees in this type of soil due to the large chucks of concert with air spaces through out. I live in northern ohio zone 6 i think. I have been racking my brain on what to do. And i have no clue. Any ideas its a mess