This section is from the book "School Gardening", by W. Francis Rankine. Also available from Amazon: School Gardening.
This crop provides a favourite salad, and although it is of comparatively small growth, it must be grown on well-worked soil. The most important consideration is rapidity of growth, for delicacy of flavour and crispness of flesh depend on quickness of development. On account of this fact, several sowings should be made at intervals, so that successional crops are secured. On some soils the Radish takes a long time to mature, and consequently the crops are stringy and coarse in flavour. Although apparently the roots or bulbs, do not penetrate very far into the soil, yet it is essential that there is a goodly depth of soil, and also a rich supply of food for their sustenance. It must be remembered that this plant possesses a long, thin, taproot which penetrates several inches into the soil in search of the food that is eventually stored in the bulb. In the school plot this crop may be sown broadcast along the borders.
 
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