Q.My Mandevilla Is Root Bound; Can I Break It Apart At The Root And Expect It To Thrive?
I can’t seem to find any info about dividing mandevilla. It is a beautiful plant and and has done well but I can’t manage it in a much larger pot (senior)! What are the chances it will survive if I break the roots apart? Thank you!

Certified GKH Gardening Expert
Disturbing the roots will, certainly, make it susceptible to diseases. If you decide to undertake this project, it will be very important to try and not break any living roots, at all. Doing so may lead to root rot. They are very susceptible to rotting.
What I would do, beforehand, is take a few cuttings. Once you have extra cuttings rooted, then you can be sure to have a replacement, should the need arise.
Here are some articles that will help:
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/repotting-mandevilla-plants.htm
https://www.gardeningknowhow.com/garden-how-to/projects/rooting-plant-cuttings.htm
https://www.gardeningknowhow.com/garden-how-to/propagation/cuttings/root-stimulating-hormone.htm
https://www.gardeningknowhow.com/garden-how-to/propagation/cuttings/honey-root-hormone.htm