26 CONIFEROUS PLANTS. 



acts detrimentally to the plants of which we are 

 speaking. * 



Both spring and autumn frosts invariably affect 

 vegetation in the valleys to ,a greater extent than on 

 the neighbouring hills, as most of our readers know 

 well enough. A September frost will destroy the 

 dahlias and many soft-wooded plants in a low-lying 

 garden, while others on an adjoining hill will wholly 

 escape. And late spring frosts in similar localities, 

 which in our uncertain climate frequently succeed a 

 period of warm weather, greatly injure many plants 

 that are easily excited into growth. Such are the 

 spring-tender firs. To enable them to succeed well, 

 they must be placed beyond the influence of undue 

 excitement, and to remove the cause is to supply a 

 remedy. But if an elevated situation cannot be pro- 

 cured, as will be the case in many localities, the next 

 best will be in a dry soil, sloping to the north, 

 and where they are screened from the influence of 

 the spring sun. 



In such situations, the yearly amount of growth 

 may not perhaps equal that which would sometimes 

 be produced, supposing the trees to escape the spring 



* Few persons are aware of the extreme variations from heat to cold 

 which occur in low sheltered valleys, and how much greater they are than 

 on elevated sites. Such extremes are highly detrimental to spring-tender 

 plants : very often after two or three weeks' or even a month's mild 

 weather, which frequently occurs hetween February and the end of April, 

 and when plants which are easily excited begin to throw out their young 

 shoots, the weather suddenly changes, and we often get in the valleys 

 from 10 3 to 15 of frost. The consequence is the loss of all young 

 growths, and the beauty of the trees is destroyed for the rest of the 

 year. If the same trees had occupied elevated situations, growth would 

 not have commenced, neither would the frost have been so severe, and 

 consequently they would have escaped unhurt. 



