32 



INTRODUCTORY REMARKS. 



depth of a quarter of an inch of light earth is • 

 deemed an amply sufficient covering for the seeds 

 of any of the above mentioned species. A fir, in 

 coming up, is among the weakest of plants, and to 

 put the seed deeper in the earth than is barely ne- 

 cessary to make it germinate, is a sure way to pre- 

 vent its offspring from ever seeing the light ; espe- 

 cially, if the ground has the least tendency to bind 

 or grow hard. The seeds of every kind of trees, in- 

 deed, ought to be covered much less sparingly, in 

 proportion to their size, than those of kitchen vege- 

 tables ; though in sowing the former, the practice of 

 the kitchen garden is often absurdly adopted. 



In giving directions for laying out a nursery, 

 Loudon recommends that earth should be forced^. 



As to tlie Aberdeen nurseries, they are now rather less exten- 

 sive than they formerly were, owing to considerable opposition 

 having started up of late years in the neighbourhood of towns 

 still farther north ; but they maintain their character as to 

 the hardiness and general excellence of the plants they pro- 

 duce. 



* I have here given the sense of Mr Loudon's words in the 

 technical language used among gardeners in Scotland. When 

 mould is brought from a distance, to improve or alter the charac- 

 ter of the soil of any piece of ground, this is called forcing of 

 earth. I loiow of no case in which this practice is necessary in 



