We are having a bit of a mosquito invasion this summer so I headed off to the local nursery to get a Citronella plant, rumored to fend off the little devils. There I was informed that it was really the Geranium Citrosa plant that I wanted. Pelargonium x citrosum 'Van Leenil.' I bought six. According to the label on the plant: "Great claims have been made for this plant as a natural mosquito repellant. Scientists have not proven this. Try for yourself. A bushy, rigorous plant. Full sun."
I scattered them all around the seating areas, hoping for the best. I can't vouch for the effectiveness of this plant to repel mosquitos. I can only report that while planting one, a mosquito landed on my cheek and bit me.