Q.What animal upends begonias?
I recently planted wax begonias in my window boxes. The next morning, all of the begonias were dug up. The only part of the plant that was disturbed were the roots.
Certified GKH Gardening Expert
You don't mention whether the leaves or roots have been chewed upon or eaten, so I'm going to guess this is a nocturnal creature, such as a chipmunk or vole, or a cat who may be looking for a place to relieve itself. I hope you're able to bury the roots and save your begonia.
Here are articles about these creatures:
Here's a begonia article for you: https://www.gardeningknowhow.com/ornamental/flowers/begonia/annual-begonia-care.htm