This section is from the book "Vegetable Gardening", by Ralph L. Watts. Also available from Amazon: Vegetable Gardening.
The parsnip is an important root crop, belonging to the family of Umbelliferae. It is closely related to parsley, carrot and celery. The roots are boiled, fried and used in soups and stews. They are also popular for stock feeding.
Deep, fertile, sandy loams grow the finest roots. Clay soils have a tendency to produce crooked and branching roots, which are not wanted by the market. Under the most favorable conditions the roots will attain a length of one foot and will be straight and smooth.
Guernsey (Student and Improved Half-Long) is planted most extensively. Hollow Crown, which is known by several other names, is also valued. Early Short Round is a small, very early variety, the roots of which are sometimes bunched with potherbs.
A full season is required to grow a good crop of parsnips. The seed, which germinates very slowly, should be sown as early as possible in the spring. A few radish seeds are sometimes sown with the parsnips. They germinate quickly, and the young plants mark the rows, so that cultivation may be begun before the parsnips are up. This method is especially desirable in soils which have a tendency to bake.
The soil should be thoroughly prepared before sowing. From to I inch of soil is sufficient covering. As the seedlings are very small and delicate at first, it is customary to use plenty of new seed, and then thin the plants to 6 or 7 inches in strong soils and 4 or 5 in poorer ones. There should be 15 to 18 inches between rows for wheel-hoe cultivation, and 2 feet or more when horse implements are to be used.
The roots may be used any time after they have reached maturity. Most gardeners who grow them in large amounts dig part of the crop in the fall, burying the roots in the ground or storing them in pits, caves or cellars. To prevent drying and shriveling in storage, they should be covered with moist sand or soil. As the roots are perfectly hardy in all parts of the North, the greater part of the crop is usually left in the ground where it was grown until suitable weather for digging the following spring. Freezing improves the quality (although this idea is sometimes refuted). The roots come out of the ground in a bright, fresh condition, and are salable on most markets. Parsnips are easily grown, and all markets should be well supplied.
 
Continue to:
plants, crops, gardening, cultivated, harvesting, food ,greenhouses, fertiliser, vegitables