This section is from the book "Save It For Winter.", by Frederick Fry Rockwell. Also available from Amazon: Save It For Winter; Modern Methods Of Canning, Dehydrating, Preserving And Storing Vegetables And Fruit For Winter Use, With Comments On The Best ... For Saving, And When And How To Grow Them.
This vegetable is one of the most valuable for winter use because of the tremendous yields it gives, its freedom from insects and disease, and the very short time required in which to mature a crop, so that it may be planted after most spring and summer vegetables and still have time to mature. Turnips are excellent winter keepers, and where there is storage room that is the simplest way to save the crop. They can, however, be either canned or dehydrated readily. The regular varieties of turnips grow so rapidly that special care must be taken to get them while they are still small and tender. Both for storing and for saving for winter use it is better to delay sowing until about mid-summer and then use a medium-sized variety of excellent table quality, such as Amber Globe, Purple Top, Strap Leaf, or white Egg.
Rutabagas are first cousin to the turnips and largely grown for winter use. They take a little longer time to grow and must be planted earlier, while the large, coarse varieties are used mostly for stock, a finegrained, tender sort, such as Bread Stone, or Golden Neckless, is as good as any turnip for table use.