Farmer John loves to experiment with heirloom vegetables and we get to enjoy the results!  But what exactly is an “heirloom” vegetable, and how does it differ from a “regular” vegetable? According to Wikipedia, “An heirloom vegetable is a cultivar that was commonly grown during earlier periods in human history, but which is not used in modern large-scale agriculture. Many heirloom vegetables have kept their traits through open pollination, while fruit varieties such as apples have been propagated over the centuries through grafts and cuttings.”