I know this is an older post but I completely see the appeal of plants for mental hygiene/ reducing anxiety & depression, it's actually the reason I started gardening.
I am a very anxious person and get easily stressed, gardening is a way for me to keep my head at bay.
When I was taking summer classes, whenever I was stressed after working on assignments or being in class all day, I would go out and maintain my parents roses. It was so rewarding because after a bit of maintaining they would begin to have bigger and more blooms!
Sometimes just taking that time to go outside and looks at my plants for a bit allows me to step out of my fears and worries and life for a bit (:
