I want to winterize my mandevillas. I have heard to rinse the roots with water to get rid of bugs.

Question

Should i wrap the root ball with peat moss until spring?

Answer 1

You can do that, but leaving it in its pot and giving it a good drenching should alleviate many insects.
Here's our article:
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/winterizing-mandevillas.htm