GRAPE REGIONS AND THEIR DETERMINANTS 35 



though the value of particular exposures is often exaggerated. 

 Let it be remembered that good grapes may be grown in vine- 

 yards exposed to any })oint of the compass, but that slight ad- 

 vantages may sometimes come, depending on the particular 

 environment of the plantation, and then solve the problem ac- 

 cording to conditions. The following are theories as to exposure : 

 A southern exposure is warmer and hence earlier than a north- 

 ern, and is, therefore, the best slope for early grapes as well as 

 for very late ones liable to be caught by frost. Northward 

 and westward slopes retard the leafing and blooming period, 

 thus often enabling the grape to escape untimely spring frosts ; 

 though to plant on such slopes may be robbing Peter to pay 

 Paul, as what is gained in retardation in spring may be lost in 

 the fall with the result that the vines may be caught by frost 

 and may fail to ripen their crop. Frost damage is usually 

 greatest on a bold eastern slope, and vines suffer most in win- 

 ter freezes on this exposure, since the direct rays of the rising 

 sun strike the frozen plants so that they are more injured than 

 otherwise by rapid thawing. In locations near bodies of water, 

 the best slope is toward the water, regardless of direction. 

 The exposure may sometimes be selected to advantage with 

 reference to the prevailing winds. • 



