468 ON USEFUL AND BOOK I. 



as the oak and the chesnut ; others thrive best when the surface 

 is covered with mosses, as the rhododendron and the erica. 



17. With respect to pruning, there are some trees that will 

 not bear the knife, as the cherry : the wood of others is often 

 hurt by it, as the pine and fir tribe. Some, again, will bear it 

 to any degree, as the thorn and the crab-apple. These peculiari- 

 ties apply to trees of some height. Most trees, when very 

 young, will bear pruning ; and many require it, to train them to 

 single stems. The silver fir, when in the nursery, requires its 

 side shoots to be shortened ; and young oaks, some years after 

 they are finally transplanted, should be cut over by the surface. 



18. Most trees require to be transplanted in the nursery- 

 ground the first or second year from the seed ; and re-trans- 

 planted from the nursery into plantations, when under four 

 feet high. Some are little hurt by this removal, as the elm ; 

 others sometimes die after it, as the spruce and the Weymouth 

 pine. Some trees die when transplanted after they are eight or 

 ten feet high, as the pine and fir tribe ; others may be trans- 

 planted at even double that age, as the lime, the elm, the syca- 

 more, and many other deciduous trees ; but a year or two pre- 

 vious to removal, their roots must be cut, and their tops pruned, 

 &c. ; a most important precaution, that should never be neg- 

 lected in removing trees above ten feet high. 



