Certain plants help one another in the garden by adding nutrients to the soil or repelling and attracting certain insects. Companion plants for potatoes include both vegetables and flowers. Beans, corn, eggplant, cabbage, peas, horseradish and parsnips all makes excellent companion plant for potatoes. Marigolds (Tagetes spp.) are beneficial, even though they are flower and not a vegetable. In turn, potatoes are a good companion crop for beans, because they repel Mexican bean beetles. Potatoes return the favor to cabbage and peas by helping with growth."
PS: Derrick, I never tried planting potatoes and cabbage near each other.