192 WATER-LILIES 



ponds are in no way shaded. A distance of 

 at least five hundred yards from the pond is 

 necessary for the windbreaks. 



CONIFERS FOR WINDBREAKS 



Evergreens form the most important class 

 of windbreaks. Among them, the Norway 

 spruce {Picea excelsa) is universally recog- 

 nised as the best for this purpose. Not only 

 is it perfectly hardy in the northern United 

 States and adapted to almost any soil, but 

 its symmetrical proportions and rapid growth 

 recommend it especially. Provided the trees 

 are trimmed yearly, this spruce can be used 

 equally well as a hedge. 



Left to itself, the Norway spruce may attain 

 a height of 150 feet, but long before this, at the 

 age of about thirty years, it will be advisable 

 to replace the trees since they become open at 

 the bottom. There are dwarf varieties to be 

 had. 



P. polita, on account of its slow growth, is 

 well adapted to use in small gardens. 



