How about I dispose of my roommates plants.
Why would you dispose of them?
It's just too sad to look at them, I'm going to bury them.
It is wrong to steal someone's things and throw them away or bury them. You should talk to them if the plants are dying and dead or start watering them.
Nah. I'm going to throw out all his plants.
They could get really angry if they find their plants missing. Are they causing a gnat or fruit fly problem there is an easy fix for that where you can keep them.