Unlike almost all other vegetables (the other main exception being asparagus), rhubarb (Rheum x hybridum) is not an annual, but a very long-lived perennial: it can live for 20 years and more. And that makes it poorly suited for the classic vegetable garden, which always emptied and replanted annually to make room for a new crop of annual vegetables. Plus, with its large size and its huge leaves, it creates enough shade to harm the growth of neighboring vegetables.
On the other hand, rhubarb is entirely appropriate for the perennial border where, with its huge, wonderfully textured leaves, its red petioles and its spectacular creamy white flowers (despite a persistent belief to the contrary, it causes absolutely no harm to the plant to let it bloom), it can even steal the show.
All it takes to be happy is rich, moist but well-drained soil and sun. And it will grow in almost any climate! If only all the vegetables were this easy!