140 AMERICAN POMOLOGY. 



to encourage early ripening of the wood, and to drain the 

 land, is one of the best means of producing this effect ; an- 

 other is the cessation of culture at mid-summer, and the 

 sowing of oats very thick at the last cultivation, has been 

 practiced, and, it is thought, with excellent effects. The 

 rank growth absorbs the superfluous moisture, robbing 

 the trees, and afterwards forms a good protective mulch 

 during the winter. The objections to it are, that it en- 

 courages the mice, which, by girdling the trees, effectually 

 winter-kills them. 



Many nursery and orchard trees often present a black 

 discoloration of the bark, which is quite unsightly, and ex- 

 cites alarm for the health of the tree. This is often caused 

 by trimming at unfavorable periods ; in the spring pruning 

 of bearing trees, the large stumps sometimes bleed, but in 

 the nursery trees it arises from cutting them, and especi- 

 ally in the barbarous trimming up, during severely cold 

 weather, when they are frozen. 



INJURIOUS ANIMALS AND INSECTS. The ' nurseryman 

 sometimes suffers fuom the depredations of some of the 

 smaller animals, which cause him great annoyance. The 

 mole, though highly recommended by the naturalists as a 

 harmless beast, who is an aid to horticulture by his insec- 

 tivorous habits, is nevertheless injurious in Jiis ways ; for 

 he often makes his run in the seed bed, or along a row of 

 root grafts, and raising them from their stations break 

 their tender rootlets, when the sun and air soon destroy 

 them. Mice, of different kinds, are still more destructive, 

 particularly in the winter, when they will often girdle 

 young trees near the collar, and do much mischief. They 

 also devour many seeds after they have been committed 



