This section is from the book "Vegetable Gardening", by Ralph L. Watts. Also available from Amazon: Vegetable Gardening.
This umbelliferous plant belongs to the celery species. The root is the edible part. It is used for flavoring, as a salad and for cooking, like other root crops. The roots vary in size from 2 to 4 inches. They may be stored during the winter under the same conditions as beets or turnips. This vegetable is of minor importance in America. It is used more largely in foreign countries, especially in Germany.
Its culture is practically the same as for celery. The early crop may be started under glass and transplanted to the open when there is little danger of severe frosts. As the plants are not blanched, less space is needed between rows than for celery when banked with earth. For the late crop, sow in the open at the same time as for late celery and transplant where the crop is to mature. Soil thrown over the roots in the fall will whiten and protect them until early winter, when they may be stored.
 
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