Yes, citronella is a fantastic mosquito repellent. I don't have a plant, but I usually mix a little bit of citronella essential oil with some peppermint, eucalyptus, geranium and lavender essential oils -- effective against mosquitoes, yet smells good.
It seems a great mix, especially peppermint´s smell (I love peppermint and eucaliptus).
I recommend you to buy a citronella. Also, is easy to reproduce. Actually, I have two plants. Those pictures are from a citronella that was part of another plant. I cut a part of the citronella, put it in water and, more or less in a week, a root grew. I planted it and... voila... a new citronella 😉
Thanks for recommendation, I'll try to find it at plant nursery, especially because it's a low maintenance plant and easy to reproduce 🙂