I agree with the sentiment on lettuce. It should effectively be grown in-store. I'd say that a few other leafy greens fit the bill -- cilantro, basil, spinach

I agree with the sentiment on lettuce. It should effectively be grown in-store. I'd say that a few other leafy greens fit the bill -- cilantro, basil, spinach, kale. There was a startup operating in my area doing just that, that recently went under. They were focused on higher-price herbs, and I think a major mistake in their model was in using valuable retail space for the hydroponic setups. A couple of stacked containers in the parking lot should be much cheaper, and produce enough volume to be competitive on lower $/kg crops like lettuce and spinach.