All systems go!
Renewable food sources in deep space are a challenge. Listen as Todd-versations chats with Ralph Fritsche, Senior Project Manager for Space Crop Production in Support of Deep Space Exploration at NASA about ways they are looking to overcome them. This agency is exploring everything from planting mediums to using advanced plant closed-system habitats, and selective breeding options with seed companies, with the intent to establish viable crop systems that will sustain the journey and future outposts. 
If it takes years to get to Mars, stopping at the local grocery store or mid-space resupply isn't tenable. Let's put our heads together and help them develop solutions.