to NGA
You can grow anything you want with whatever you want. The whole idea of companion planting is to give plants the best advantage you can in the space you have. The classic example of companion planting is planting corn, climbing beans and pumpkins together. The corn supports the beans, the beans feed the corn and the pumpkins bask in the shade.
In my mind, tomatoes are hard to pair with anything. I have planted beets, radishes and carrots with them but I have never been happy with the results because I have to wade through stinky tomato plants to get to my root crops. I have also planted running squash with tomatoes because the tomatoes stand still and the squash wonder 10 feet away before growing squash. Putting something under tomatoes is a good idea because tomatoes hate warm feet.
I am growing cucumbers and Okra in the same hill this year but my thinking was that cucumbers stay short and appreciate some shade and okra grows tall. Nobody seems to be arguing.
Mix your garden up some by planting veggies and flowers interspersed, not planting in rows and not putting all of one type of plant together. Before I moved to the desert and water wasn't such an issue (everything is on drip now), I used to till my entire plot, mix my seeds together and stand back and throw them at the garden. I had some great gardens.
Daisy