52 SEED AND ITS NEEDS 



Thinning is not only done to give the plants more room to 

 expand and to grow, but also to provide them with sufficient 

 space from which to gather plant food. It should therefore 

 be done as soon as possible after the plants are up. The early 

 elimination of the surplus plants prevents any loss of the 

 available food. 



Thinning is accomplished in several ways according to the 

 crop : (1) By weeders or implements designed for the purpose 

 of cutting out the surplus plants, and (2) by hand. Hand 

 thinning is usually practised on such plants as the garden 

 beet or the onion. 



Transplanting of Seedlings, — One of the principal reasons 

 for the transplanting of the seedling is to develop a good root 

 system. An ideal root system is one that has a great number 

 of short branches, bearing many small root hairs. Such a 

 root system provides a large area for the absorption of food 

 material in a comparatively small space. An expression for 

 this condition often used by gardeners is "ball of root," 

 which means a well-developed and compact root system. 

 The formation of this ball takes place only after the seedling 

 has been transplanted several times. It is formed when the 

 larger roots are broken off, which causes them to branch and 

 to make a number of small fibrous roots. The root system 

 then is a network of fine root hairs, all of which take food 

 from the soil. Such a root system is easiest and is most readily 

 obtained by the root pruning which takes place during 

 transplantings. With many plants repeated transplantings 

 are an advantage. The first transplanting is most important. 

 It consists in the pricking of the seedlings out of the seed 

 bed. Several precautions must be observed, of which the 

 most important one is the preparatory treatment of the seed- 

 lings before transplanting. A few days previous to the time 

 the plants are to be taken up, withhold the water supply 

 and ventilate the plants freely to harden the tissue of the 

 seedlings if they have been grown in a hot-bed or cold frame. 

 An hour or two previous to the transplanting of the seedlings 

 give them an abundance of water. In removing the plants 

 from the seed-bed avoid injury to the roots, and in resetting 

 them pack the soil firmly about the roots so that they will 



