Q.Why is there a hard, wartlike covering on entire trunk of my snow fountain weeping cherry tree?
My landscaper planted this new tree in the spring. I have tried to find out what the covering is from numerous sources, including landscaper. I wonder if it has to do with grafting and if it should should remain on trunk??

Certified GKH Gardening Expert
It would be helpful to see a photo. One possibility is scale. Another is crown gall, but if it covers the entire trunk of the tree, you should probably contact your local extension agency to be sure about it.
https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/snow-fountain-cherry-info.htm
Here's an article about crown gall: https://www.gardeningknowhow.com/edible/fruits/cherry/what-is-cherry-tree-gall.htm
Here's an article about scale:
https://www.gardeningknowhow.com/plant-problems/pests/insects/control-plant-scale.htm
Here's a link for finding your closest agricultural extension service: https://www.gardeningknowhow.com/extension-search?zip=+07424&radius=100&services_search_action=search&submit=Search