There are two types of turnip: early- and main-crop. Both are round and slightly flattened with wispy roots. Early turnips have a pearly green-white skin tinged with purple and tender flesh with a peppery, slightly sweet flavour. The green tops of turnips can be eaten when young and tender and have a peppery, slightly bitter taste much prized in Europe and the southern US.
Early-crop turnips are in season from April to July; main-crop turnips from August to March. Look for turnips with smooth, undamaged skin and without brown spots, holes or spongey patches.
Early-crop turnips are usually sold washed, in bunches. They are at their sweet, nutty best when young, and can be as tiny as golf balls.
Early-crop turnips will keep loosely wrapped in a paper bag for about two weeks in the bottom of the fridge as long as you remove their leafy tops. Main-crop turnips will keep in a cool, dark place for much longer.
To freeze early-crop turnips, trim, peel and dice them, then blanch, cool and pack into freezer bags. Cook from frozen.
For main-crop turnips, cook, drain and mash them, then freeze in rigid containers.
Early-crop turnips can be lightly cooked in butter, braised or roasted or even eaten raw in salads when very young. Main-crop turnips are larger and coarser, more similar to swedes, and as the bulbs get bigger, the flavour becomes more pronounced.
Main-crop turnips can be boiled and mashed or used in soups and stews.