Catnip, Rosemary, annual marigolds, also Citronella grass, but thats a tropical plant which will need protection in winter.

Not sure how effective these will be frankly - if you have standing water in your garden, get rid of it (empty pots, etc). If you have a pond, put a pump in to keep the water moving.

Otherwise, I always found the most effective thing was citronella candles when outdoors, insect mesh screen over the back door, nets at the windows, and never turn on the lights inside the house when the doors and windows are open or uncovered. Lastly, I had two other bits of kit (one of my sons was particularly attractive to these and the bites always got infected) - one was a litte thing looked like a lighter, emitted a high pitched tone, and a plug which took tablets which emitted a mosquito repellent, both for use in the bedroom when he slept.