I don't have alot of experience with this, but...

The mosquitos in my wet swampy back yard are not particularly bad. I had a co-worker come over one day and I commented on the lack of mosquitos to him. He indicated that it was due to the large number of Sweet Gums on the property. There might be something to this as the turpines in the leaves are fairly strong.

Another co-worker indicated that Weeping Willows, while very pretty, attract mosquitos. I have a few sickly willows, but don't see much difference in the mosquito count around them.

As an experiment, I'm going to plant tobacco this spring to look at the insect repellent properties of this plant (works with some bugs, don't know about mosquitos).

Oh, I really like this idea! Guess I must be planting the wrong kinds of things, but I'd like to know which plants would repel them. Think scented-leaved pelargoniums (geraniums) are supposed to repel them--didn't notice any less around the rather large one I had last year. The only things I'm sure of are putting up bat houses and houses for purple martins. Have a friend who had purple martin houses on all four sides of her house in Erath and she had absolutely no mosquitos. Haven't asked if the martin houses fared any better than her own house and yard, which she is still working on--may be done by Christmas. Ugh!

anything that has big leaves, or thick such as shrubs, will generally attract mosquitos. there are so many different kinds of mosquito that what one breed hates another thrives on.

i go full chemical on them every 2-3 weeks and keep the population down to a mere cloud instead of solid mass. no kidding, if i don't spray you cannot go in my yard after dusk. they will cover every sq inch of you. by spraying i keep them down enough that deep woods off works.

they seem to LOVE my cedar trees, crepe myrtles, and my bushes, not so much the wisteria vine and rose bushes.

I already have mosquitoes... UGH!! Off Lamps work really well if you don't like using spray. They work better than anything else I've tried. We've had rain all morning so I'm headed outside to dump any water around the yard.

I did some searching on the net and came up with some sites with information for you. Rosemary was one of the plants that repel which works for me since I love rosemary. Now I have a reason to grow more of it :)

http://www.basic-info-4-organic-fertilizers.com/companionplants.html

http://www.ne-design.net/rain-barrel-mosquitoes.html

http://www.homeandgardensite.com/companion_planting.htm

Bugs are said to dislike wax myrtle.