96 QUINCE CULTURE. 



their places, in which case it is likely to be winter-killed. 

 A mulch sufficient to protect the roots from freezing 

 during the winter is a wise precaution, not only to pro- 

 tect the newly-planted trees from intense cold, but will 

 be a safeguard against winter-killing in those well estab- 

 lished. It has been found highly beneficial to trees to 

 have a mantle of snow cover the ground all winter, be- 

 cause it protects the ground from sudden changes. A 

 winter rain freezing on the limbs will do little harm, 

 unless accompanied by winds, because there is no danger 

 of drying out the sap. The cold may be severe enough 

 to weaken the vitality of fruit-buds, and they may all 

 drop off after they have blossomed. 



Trees are able to endure greater cold in a dry atmos- 

 phere than in a moist one. In elevated situations, trees 

 will endure a severer temperature than in valleys or low 

 down the hill-sides. 



It will operate favorably to so cultivate the trees as to 

 secure an early growth and ripening of the wood, that it 

 may be in the best condition to endure the severity of 

 winter frosts. When stimulated to grow very vigorously 

 late in the season, the young wood is more likely to suffer 

 than that produced earlier in the season. 



The thermometrical and hygrometrical conditions act 

 together, and the hardiness of trees will be determined 

 by the power of the tissues to withstand the pressure 

 that will burst them if they contain too much sap, or to 

 shrivel them by drying out their moisture, and so de- 

 stroying their vitality. 



A wise precaution against winter-killing in sections 

 where there is danger, is not to cultivate late in the 

 season. The culture that stimulates a late growth of 

 soft wood that does not ripen before the severity of 

 winter sets in is to be avoided. The immature wood is 

 easily injure:!, the grain is ruptured by freezing and 

 thawing, and the disorganized cells in spring are no 



