86 



causing a water-film to envelope each without closing up 

 the air-ways around it, and the absence of colloidal clay to 

 interfeie with capillarity, applies to the requirements of an 

 orangery with more force than to those of an ordinary 

 orchard. Where the OAvner has to complain of the gradual 

 decay of his citrus trees, one dying out after another, 

 there are mostly two causes at work, acting singly or to- 

 gether. They are unsuitable conditions of soil and 

 treatment, and insect and fungous plagues. 



The whole citrus tribe differ considerably from the 

 ordinary orchard trees in their relation to the yearly out - 

 put of new wood, foliage and fruit. Hence they cannot 

 be treated in the routine methods of pruning which have 

 been described, nor can they be shaped to the truncated 

 cone pattern which answers so well with dwarf trees gener- 

 ally. It is absolutely necessary to encourage the axial 

 growth and thus have a tree with a more or less pyramidal 

 outline. This varies considerably by lengthening of 

 laterals^ so that the pyramid may become very obtuse at 

 the top, or the head may tend towards a globular shape. 

 But in all cases well-grown examples keep their main axis 

 undisturbed, and naturally resemble the style given to 

 other trees by pruning to standards. Generally speaking, 

 citrus trees balance their growth very evenly if they have 

 started well and are in a suitable aspect ; consequently, 

 the pruning knife has but little call to interfere. All that 

 is necessary is to cut out dead wood and the long ill-placed 

 wastrels which often fill up the centre of the tree and pre- 

 vent sufficient access of air and light. Whenever a cut- 

 has to be made near an inch in diamater, the edges should 

 be carefully pared all round, so as to ensure adherence of 

 the bark along the line of section, and the wound brushed 

 over with a little oil- varnish or a solution of shellac in- 

 spirit. Tar should not be used, except as a matter of make- 

 shift. Mature trees blossom and bear the fruit very near the 

 end of the branchlets, and the next season's fruiting growths 

 start from behind as new laterals, which overtake the previous 

 season's bearing-twigs, just beyond them, and fruit in their 

 turn. It is this peculiarity which produces the evenly rounded 

 outline of a well grown citrus tree, and also renders un- 

 necessary the continual shortening in which is required for 



