Why do you think that mosquito repellent plants do not work?
I am growing the "Citronella plant" right now. It works very well. Mosquitoes and other insects are attracted by CO2, and cuts /wounds. Those two things are impossible to stop. Especially breathing. Several combined plants and other diversions and yard work all work together. It has been a very wet Year where I live. Even one plant helps.
Certified GKH Gardening Expert
That's wonderful if it works for you. We consult the university cooperative extension websites for information that is research based. According to their sites, the citronella plants would have to be crushed (to release oils) and rubbed on your skin to get any benefit. Their studies show just having the plants in the landscape do not help. This article below states that lemon thyme actually works better than the "mosquito" plants so maybe we should make sure that is in our yards!