according to companion planting guides the follow list do well with the brassicus family:-
Potatoes, celery, chamomile, sage, thyme, mint, Nasturtium, pennyroyal, rosemary, lavender, beets, Spinach, Chard, onions, Marigold, Carrot, Cucumber; aromatic plants are said to deter cabbage butterfly.
it is advised that they dislike dill, strawberries, tomatoes, and pole beans. but others may have had no problems combining these :-\, so they may get along just fine.