85 



demanded special care in the preparation of the soil and in 

 the drainage and aeration. Perhaps this touchy fastidious 

 disposition reaches its climax in heaths, azaleas and rhodo- 

 dendrons. So short is the portion of their root-fibres that 

 is physiologically active, that a very slight deprivation of 

 the air they require brought about by over- water ing, or a 

 temporary lack of moisture, is enough to kill them. The 

 gardener therefore makes his potting composts for these 

 plants very porous by the addition of fibrous peat and sand, 

 is extra careful to have plenty of drainage- crocks at the 

 bottom of the pots, and to water just enough and no more 

 at short intervals. Now the orange and the citrus tribe 

 generally are far from being equally fanciful, but their con- 

 ditions of health and longevity so far as the roots are 

 concerned are precisely similar in kind to those of the 

 above typical series of plants, and differ only in degree. 

 Consequently citrus-culture, to be a permanent success, 

 must be founded upon fulfilment of these natural peculi- 

 arities of the tribe. All citrus trees require certain special 

 cares in planting from the nursery. Their roots are natu- 

 rally horizontal in direction and spread near the surface, 

 keeping to the best and most fully aerated part of the soil. 

 It follows that in planting, the roots should be spread well 

 out upon the bottom of a hole of proportionately large 

 diameter, and made to radiate as equally as possible. If 

 the locality requires that the tree be supported for the first 

 few years because of prevailing winds, the stake, with its 

 lower end charred to preserve it, may be driven down into 

 the subsoil at the time of planting, and thus the operator 

 will escape the chance of destroying a principal root-branch 

 by forcing it in blindfold after he has covered up the roots 

 out of sight. As these trees are liable to gumming and 

 bark- canker at the collar if it be kept wet, it is of great 

 importance that they be not set deeper than they had pre- 

 viously stood in the nursery. There will always be a little 

 settlement after planting, because the earth employed in 

 filling is very loose, and this sinking may be allowed for 

 within reasonable limits. 



Whatever has been said respecting the physical charae- 

 ter of a perfect soil, viz., the loose texture of its particles 

 admitting air throughout the mass, their surface attraction 



