434 SHIFTING. 



orchard of the same kind of fruit; a wall-border, in whicl 

 fruit-trees have been long grown, becomes at last insensible tc 

 manure, and requires to be renewed ; and, not to dwell upon ar 

 undisputed fact, Dahlias do not " like " the soil in whicl 

 Dahlias were grown the previous year. What is the real caus( 

 of this? Not exhaustion of ordinary fertilising ingredients 

 because that exhaustion is made good and yet to no purpose 

 Are we to assume, what seems to be the fact, that land contains 

 something mineral which each species prefers to feed on, anc 

 which is not contained in ordinary manure ? This wiU b( 

 further considered in the final chapter on soil and manure. 



It is not, however, merely for the purpose of removing 

 deteriorated earth or adding manure, that shifting is important 

 in all potted plants the ball of earth, by the continual passag* 

 of water through it, is in time reduced to a state of hardness 

 and solidity unfavourable to the retention of moisture or th< 

 growth of roots, and this is of course cured if the operation o: 

 shifting is judiciously performed. I must, however, confess ] 

 have seen gardeners contented with lifting a plant with a hare 

 old matted ball, out of one pot into another of a little largei 

 size, shaking some particles of fresh earth in between the bal 

 and the side of the pot, and pressing the whole down with as 

 much force as the thumbs can give. Do such men deserve th( 

 name of Gardeners ? 



It is found that the roots of potted plants invariably direc 

 themselves towards the sides of the pot, as must indeed neces 

 sarily happen in consequence of their disposition to grov 

 horizontally. Having reached the sides, they do not turi 

 back, but follow the earthenware surface, till at last they forn 

 an entangled stratum enclosing a ball of earth ; then, if no 

 relieved by repotting, they rise upwards towards the surface, oi 

 they attempt to force themselves back to the centre. Th( 

 greater number of roots are, however, always found in contac 

 with the porous earthen sides of the vessel ; and especially al 

 the most powerfully absorbent, that is to say the youngest 

 parts. They are, therefore, in contact with a body subject t( 

 great variations of temperature and moisture, in consequenci 

 of exposure to the sun, or to a dry air in motion, unless i) 



