Mint, lemongrass, lavender… nothing works as far as I’m concerned (Ontario, Canada). Same with ultrasonic repellants, burning coils, torches, TiO2 bulbs, taking vitamin B or garlic.
What does work for me are devices like the mosquito magnet: they burn propane to produce humidity and CO2 and use a fan to blow that through an optional chemical attractant like octanol while using the use the suction of the other side of the fan to draw the little bastards into a mesh basket where they are trapped until they desiccate.
These machines serve two purposes: they take care of the mosquitoes today and over time they break the reproductive cycle of the mosquitoes in the area which after ~6 weeks DRAMATICALLY reduces the problem for the rest of the season. A 20lb tank of propane lasts about a month. The downside is that these machines tend to be VERY finicky and you have to futz around with them after the first season to get them working again. Not great for a $500+ device.
Additionally, building bat houses and encouraging swallows to nest in the area also do wonders: both of these creatures are voracious mosquito hunters (and barn swallows are my favourite bird).