The turnip's reputation has risen, and more often fallen with the fortunes of the societies that grow it. In good times, it gets elbowed out to make way for more posh roots, like parsnips and celeriac. Funny how forced frugality reminds folks that cheap doesn't necessarily imply worthless or crude.
Mood swings and prejudices aside, the practical truth is that the turnip, humbled in post-war turnip soups or prettily dressed up in a celebrity chef gratin, is an exceptionally versatile and economical food. The top greens cook down easily like spinach and have some of the peppery zing of mustard greens. And the charming bi-colored tap root – part white, part lavender – can either fill out a lean stew or casserole as a bit player, escort a savory hummus in a beet-colored Middle Eastern pickle, or stand perfectly well on its own in an elegant Potage Freneuse.
Its abundance in the markets right now is a testament to its undemanding requirements – mild weather (45 to 75 degrees) and 30 to 60 days from seed to harvest, which is why you see them mostly between October and March. Look for heavy, unblemished roots between two and three inches in diameter. Larger roots are tougher and sometimes woody if really big (four inches plus) but can still be used in recipes requiring long cooking or pickling times – just remember to peel them first. That little rosette of green on the top where the leaves have been trimmed off also tells a story – the turnip continues producing greenery when out of the ground. The more stalks present in the rosette, the older the turnip.