INJURY IN NURSERIES AND ORCHARDS. 25 



attacks below the surface and except under cover of snow rarely 

 extend them above ground. They sometimes consume the entire 

 roots of small apple trees so that only the trunk is left (PI. Ill, 

 fig. 1). Experienced nurserymen prevent serious injury to standing 

 stock by clean cultivation. Stock that has been taken up in the fall 

 and " heeled in "' or kept in storage pits is, however, liable to attack, 

 especially if covered by straw, leaves, or other litter. Hence for 

 protection from freezing a loose covering of soil is better than litter. 

 Winter seed beds of conifers, oaks, and nut-bearing trees are often 

 attacked by field mice and need to be carefully protected from them 

 as well as from white-footed mice {Peromy sens'). Small pine trees 

 in the nursery also are liable to injury, since their low branches 

 usually furnish cover for mice. 



Among the nursery stock injured by field mice are apple, pear, 

 quince, plum, peach, cherry, crabapple, sugar and Norway maple, 

 chestnut, black locust, Osage orange, sassafras, alder, white ash, 

 mountain ash, various oaks, cottonwood, willow, pine, and wild 

 cherry trees; also blackberry, raspberry, rose, currant, and barberry 

 bushes, as well as grape vines. In the Arnold Arboretum, Jamaica 

 Plain, Mass., during the winter of 1008^. meadow mice destroyed 

 thousands of trees and shrubs, including apple, maple, sumac, liar- 

 berry, buckthorn, dwarf cherry, snowball, bush honeysuckle, juniper, 

 blueberry, dogAvood, beech, iMid larch. Plants in nursery beds and 

 acorns and cuttings in l)oxes especially were harmed." 



INJURY TO ORGIIAEDS. 



Trees transplanted from the nurseiy into the orchard are in more 

 danger from field mice while the outer bark is green and tender, but 

 there are instances in which trees 5 and 6 inches in diameter have been 

 attacked and killed by them. Most farmers are inexperienced as 

 orchardists, and plant fruit trees only for family use. Engrossed in 

 the production of other crops, they often neglect the orchard and per- 

 mit annual grasses or Aveeds to grow up, which afford cover for mice. 

 Often, too, cloA'er or orchard grass is sown in the orchard as a cover- 

 ing for the ground, and the heavy growth left for Avinter mulch is 

 augmented by fallen leaves. Under such conditions it is not strange 

 that mice injure the trees. It is remarkable, indeed, that so many 

 orchards escape injury. That they do so may in part be attributed to 

 the fact that they are often near dwellings, where hens scratch and 

 cats prov.l. 



Attacks upon orchards by mice are not ahvays accomplished under 

 cover of snow, nor ai-e they confined to winter. They frequently 

 occui" in sunnner, often in Sei^tembei-. During the winter of l!>Or>-() 



" Rostoii TDiiiscriiil. Ai»ril IC, 1004. 

 lUTUO— No. 81— <I7 4 



