Hello,

It’s definitely better to leave the snow on as an insulator from the temperatures predicted for tonight. Depending on the tree, some flowers may survive with little damage, such as crabapples and redbuds, but others, such as magnolia have no tolerance for cold temperatures and will likely not survive even with a layer of snow. Trees whose flower buds have not yet opened should not be in danger.

This article has some information from Secrest Arboretum about the late winter weather we’re experiencing.

https://www.the-daily-record.com/story/news/2021/04/20/freezing-temperatures-threaten-crabapple-bloom-secrest-arboretum/<personal data hidden>/

And this video features an interview with Lucas County Extension Educator, Amy Stone, with further explanation about protecting plants.
https://www.13abc.com/2021/04/20/local-expert-shares-ways-to-protect-your-plants-during-the-cold-snap/