THE TKEES OF AMERICA. 59 



healthy growth of those trees which dislike to be moved. Leaves, or straw, or 

 almost any waste vegetable substances, are good for mulching, and they also 

 constitute food for the trees. But the best material I have found for this 

 purpose, especially for fruit trees, is weeds, used before seeding, in July and 

 August. The stone is removed from around the tree, the weeds put in place, 

 and the stones returned to their former position. I pave around all my trees, 

 and in many cases allow this pavement to remain for years. With some little 

 care in placing it, it may be rendered quite ornamental. In lawns, where it is 

 required to keep grass from growing close to trees, this paving process is an 

 admirable one. 



" The cost of moving trees of six or eight inches in diameter one mile, is not 

 over ten dollars each. From one foot to eighteen inches, the cost will be from 

 seventeen to twenty dollars. This includes all the expenses of transplanting." 



There are several native species of the poplar. The River Poplar — P. Icevi- 

 gata — is perhaps one of the finest. Emerson says of it, "The river poplar is 

 a noble tree, rising often to the height of eighty feet or more, with a fine long 

 open head. The river poplar deserves to be introduced into cultivation as an 

 ornamental tree. It is much the tallest and most graceful of those which grow 

 naturally in New England. It grows readily from cuttings, and by selecting 

 these from the sterile tree the evil complained of in the cotton of the Balm of 

 Gilead will be avoided. It has been extensively introduced into England and 

 France, where it is valued for its beauty and its wood." The wood of all the 

 poplars is very durable if kept dry, Loudon quotes an old distich, said to be 

 inscribed on a poplar plank, which he says is strictly correct : — 



" Though heart of oak be e'er so stout, 

 Keep me dry and I'll see him out." 



The Necklace Poplar, another species, is said to be the most rapid growing 

 tree known. Emerson mentions one at New Ashford, some sixty years of age 

 in 1838, when he measured it ; it was then twenty feet five inches in circum- 

 ference at the smallest part between the ground and the branches. This tree, 

 in the neighborhood of London, grows between thirty and forty feet in seven 



