286 APPLICATION OF PRINCIPLES. 



is required in the selection of a suitable season, damp, 

 and not too cold, for a deciduous tree, is still more es- 

 sential for an evergreen. It is, therefore, most extra- 

 ordinary that it should ever have been the practice to 

 defer the planting evergreens till late in the spring, 

 upon the supposition that it is the very best season 

 for them, and that midsummer even is a proper pe- 

 riod ; as if cold winds, accompanied by from 20° to 

 30° of dryness in the air, which is not more than 

 •500 or -357 of moisture, with a bright sun beating 

 on the roots which are exposed, and exciting the ac- 

 tion of the perspiring surface to the utmost extent of 

 its power, were external conditions with which the 

 gardener has no concern : and yet, as Mr. Macnab 

 justly observes, half a day's sun in spring and autumn 

 will do more harm immediately after planting, than a 

 whole week's sun from morning till night in the mid- 

 dle of winter. 



The Holly, says the writer in the Horticultural 

 Transactions^ does not succeed well, if transplanted at 

 any other season of the year than the end of April 

 or beginning of May ; at this time the buds are just 

 breaking open into leaf, and I have rarely failed of 

 success in transplanting small, or even very large old, 

 trees (ii. 357). Although such statements cannot be 

 too strongly contradicted as guides to practice, yet it 

 is not difficult to explain their origin. As evergreens 

 are never deprived of their leaves, so they are never 

 incapable of forming roots; on the contrary, they 

 produce them abundantly all winter long, and rapid- 

 ly at any other period of the year which is favourable 



