I'm never without this Mosquito Repellent Plant on my Porch....

Or deck or outside swing. Citronella scented Geranium is not only beautiful with it's  pretty  two-toned pink flowers but it keeps away mosquitoes too. I put a potted one on the porch and deck so I can grab a leaf and rub it on my arms, neck and ankles - any where these buggers bite. Keeps them away and smells wonderful too. The pictures are of a whole tray of them for sale in the greenhouse yard.

It's not a perennial here (zone 6B) but I winter it over in a sunny window. Easy to root from cuttings too!