336 TREES AND SHRUBS 



other plants of which portions are apt to die or 

 wear out. These are proper to the pergola, whose 

 permanent substructure makes it easier to cut 

 away and renew those of its coverings, whether 

 structural or growing, that are liable to partial 

 decay. 



A great many delightful things may be done 

 with these green alleys and green shelters. Much 

 interest is already aroused in the pergola, and 

 when thinking of this it is well to consider these 

 other ways of adding to the comfort and charm of 

 our gardens. One thing, however, should be care- 

 fully considered. It should be remembered that 

 where a path is made more important by passing 

 under trained green growths it should have some 

 definite reason for being so accentuated, certainly at 

 one and desirably at both ends. It often occurs 

 that in laying out ground the owner wishes to 

 have a pergola, as it were, in the air, and when 

 there is nothing to justify its presence. It should 

 not be put at haphazard over any part of the 

 garden walk. If of any length, it should distinctly 

 lead from somewhere to somewhere of importance 

 in the garden design, and should, at least at one 

 end, finish in some distinct full-stop, such as a 

 well-designed summer-house or tea-house. 



Another important matter is that a pergola or 

 green alley, in the usual sense, should never wind 

 or go uphill. It is not intended by this that 

 shading coverings cannot be used in such places, 

 but that they would want especial design, and it is 



