My Russian was only raised on red leaf lettuce, so it was difficult getting him on a proper diet. He still doesn't just eat anything, but it's been much better than where it was at. That's been two years now. Just keep working on it and it will get better!
There are many varieties of Dandelions. Mine like the ones that have a almost translucent tube like stem and that only grow about 5" to 7" tall on average.