Q.Geiger Tree In Northern Climates?
My parents and two of my siblings are buried in a cemetery in Wisconsin. The soil is very sandy. I know that the tree is primarily a southern coastal tree. Has there been a species or a mutation that have been developed that can withstand the cold winter climate in the Midwest?

Certified GKH Gardening Expert
This tree thrives in tropical climates. Our experts say the white-flowered relative Cordia boisseri is more cold tolerant, but that doesn't mean it can survive a Wisconsin winter.
I'm going to suggest that you contact one of these local extension services for advice: https://www.gardeningknowhow.com/extension-search?zip=54494&radius=50&services_search_action=search&submit=Search
Here's our article about Geiger trees: https://www.gardeningknowhow.com/ornamental/trees/geiger-tree/geiger-tree-information.htm