There is a tropical grass with the common name of Java citronella — Cymbopogon winterianus, is that what you mean? The plant is grown in Southeast Asia and is steam distilled to extract an essential oil known as citronella.
As noted, it is a tropical plant. Not hardy in your climate. More info
https://tropical.theferns.info...
Edit to add awhile later: got thinking that it seemed unlikely that you were asking about the above plant. There is also Pelargonium citrosum, called citronella plant, reputed to repel mosquitoes. That's probably what you mean. It's also not hardy in your climate, but easy to overwinter indoors and/or grow from cuttings
Citronella Plant (Pelargonium citrosum)
