A friend shared a link to a page listing flowers that would help your vegetables thrive, naturally I checked it out. ;)
According to the link, if you grow plants in a greenhouse, go with French Marigolds as they'll deter white-flies.
Lavender and Sedum will attract bees to your garden plots and your vegetables will be pollinated while they visit. But according to this link, the plant you should have in your garden no matter what, is the Sweet Pea, especially those with "odoratus" in the name.
Now I love the scent of sweet pea, especially over the scent of the Magnolia and the Mimosa. I just can't stand those particular scents. So I think I'm going to get some Sweet Pea just to have around the place, as well as grabbing some of that mint from my mom's yard that's attempting to take over. :)