56 Bush-Fruits 



HARDINESS 



In the eastern states, and probably throughout the 

 greater part of the country, red raspberries are less hardy 

 than black-caps. According to Kirkpatrick 1 the reverse 

 is true in Minnesota. Some varieties are seldom injured in 

 favorable locations in middle latitudes of the United States. 

 The most common condition is that the tips are killed 

 back somewhat but ordinarily not farther than it would 

 be desirable to cut them at pruning time anyway. 



It, seems probable that lack of hardiness as frequently 

 comes from want of ability in the leaves to endure the 

 hot suns of summer as from lack of ability in the canes to 

 endure the cold of winter. If by any means the function 

 of the foliage during the growing season becomes impaired, 

 the vitality of the plant is lessened, and it goes into winter 

 poorly prepared to meet the conditions laid upon it during 

 that period. Hence it seems but reasonable that lack of 

 hardiness, or winter-killing, may result from insect or 

 fungous injury inflicted during summer, as well as from 

 unfavorable climatic conditions. It is an interesting fact 

 that small, late-growing canes generally stand the winter 

 better than the more vigorous ones of the whole season's 

 growth. Cuthbert canes produced at the Cornell gardens, 

 after cutting away all young canes early in July, came 

 through the winter in better condition than the earlier, 

 undisturbed canes in the other part of the same row 

 These later canes were alive to the tip in spring. At the 

 time the leaves were opening they were more uniformly 

 green and farther advanced than the others. They pro- 

 1 Minn. Farmers' Library Extension, Bulletin No. 16. 



