OF POTTING. 275 



caused to spring from its larger branches and stems ; 

 and, in all cases when trees can he made to retain their 

 health in exposed pots, the period of the maturity of 

 their fruit is very considerably accelerated. {JSort. 

 Trans., vii. 258.) 



It seems to be nothing but the complete drainage 

 to which they are then exposed, that makes the 

 Orange and all its tribe, naturally inhabitants of the 

 hill-sides of the temperate parts ,of Asia, thrive 

 best when the roots come in contact with the sides of 

 the pots, &c., in which they grow. In all cases, the 

 drainage should be most carefully secured, by placing 

 an abundance of broken tiles, potsherds, &c., in the 

 bottom of a pot, so as to prevent the stagnation of 

 water (page 119) about the roots. 



Mr. Macnab, in his excellent practical treatise upon 

 the cultivation of Cape Heaths, points out very forci- 

 bly the value of good draining to that class of plants. 

 There is scarcely any danger, he says, of giving too 

 much draining; and, in order to eflf'ect this essential 

 object still more perfectly, he, in shifting his Heaths, 

 constantly keeps the centre elevated above the gene- 

 ral level of the earth in the pot or tub, so that at 

 last each plant stands on the summit of a small hillock. 



In order to counteract the risk of excessive drain- 

 age, without in reality diminishing it, great advan- 

 tage is derived from the introduction into the earth 

 of fragments of some absorbent stone. Mr. Macnab 

 uses "coarse soft free-stone, broken into pieces from 

 one inch to four or five inches in diameter ;" because 

 in summer these stones retain moisture longer than 



