When I bought the tulips, I also picked up Growums gardens for Ruben. They can be found here. I think they are very clever. You buy a themed garden kit and get a code to register it. They have games and videos with cartoon vegies to go with your garden. My sister compared it to "webkins, but better." It is nothing new that getting children to help garden helps teach good eating habits, or that children love to grow things. It is almost magical. It also requires patience. A program that include video games with learning which bugs are bad for your garden, and progressive videos that teach you the next step needed, helps keep them interested.
I bought the taco garden as something familiar, and the stir-fry with mostly familiar items. The themes help incorporate the idea that eating vegetables are fun. My daughter wants a salad one for her apartment.