Buy Red Cabbage Seeds from the Traveling Cart on Fridays and Sundays
Buy Red Cabbage Seeds from the Oasis after unlocking it in Year 2
Find Red Cabbage in the Skull Cavern as a rare drop
Get Red Cabbage from the Seed Maker by processing Red Cabbage
Grow Red Cabbage from Red Cabbage Seeds in Summer
Enable Community Center bundles completion to unlock Red Cabbage availability in Year 1 through the Traveling Cart only if the game version or settings allow it