RECOMMENDATIONS TO FARMERS. 61 



This can be accomplished most readily by dragging a heavy log or 

 stick of timber several times around each block of trees, packing the 

 snow so firmly that mice can not tunnel under it. If this precaution 

 is taken promptly after the first snow fall, subsequent falls will re- 

 quire but little attention. Some nurserymen plow furrows on both 

 sides of the trees, throwing up the soil in a ridge along the rows ; but 

 the expedient is of doubtful utility. 



Much of what has been said about the nursery will apply as well 

 to young orchards. Clean cultivation is equally important, and 

 under no circumstances should matted grass be allowed around the 

 trunks of trees or litter be permitted to accumulate in the orchard 

 or along its borders. In case of heavy snows, dragging should be 

 resorted to or the snow stamped down carefully around each tree. 



In the absence of snow, a cleared space of about 18 inches radius 

 about the trunk of each tree is enough to prevent damage. The 

 surface of the cleared space should be as smooth as possible, as even 

 clods of earth may afford shelter for mice. 



If any part of the orchard is so located as to be subject to snow- 

 drifts and mice are abundant in the vicinity, tree protectors should 

 be used. These may be had of dealers for 60 to 75 cents per hundred 

 or they may be made by the farmer. Those offered for sale are usu- 

 ally wood veneers of some sort. In California the wood of a yucca 

 {Yucca hrevi folia) is utilized for the purpose. Strips of wire cloth 

 make excellent protectors, and tarred paper is a favorite with some 

 horticulturists. The wire cloth or paper is cut into strips about 7 

 inches wide and at least 15 inches long. A strip is secured around 

 each tree with wire or cord. Tarred paper should never be used on 

 very young trees, and when used on others should not be left in place 

 during the summer, since it may injure the growing tree. 



Various paints and Avashes have been recommended to prevent 

 attacks of mice and rabbits in orchards. The majority of these are 

 without merit and some of them are liable to kill young trees. Some 

 of the washes require renewal after every hard rain. In experiments 

 with a wash of whale-oil soap, crude carbolic acid, and water, for 

 apple trees, it was found that in about forty-eight hours the carbolic 

 acid had so far evaporated that mice renewed their work upon the 

 bark. Blood and grease, said to give immunity from rabbit attacks, 

 would invite the attacks of field mice. 



Eeports recently received by the Biological Survey seem to indicate 

 that the ordinary lime-and-sulphur wash, recommended for the winter 

 spraying of trees to destroy the San Jose scale, is an effective pre- 

 ventive of the attacks of both mice and rabbits. Personal observa- 

 tions during the winter of 1906-7 indicate that this claim is well 

 founded. Several correspondents state that they have tried the wash 

 successfully, and the matter is worth further investigation. The wash 

 is very cheap (from 1 to 2 cents a gallon when prepared in 45 to 50 



