38 POPULAR FRUIT GROWING. 



the peach for stocks. The plum takes well on the&e and they 

 are commonly used in milder sections, but with such roots, trees 

 are often injured or killed out entirely in severe winters in those 

 sections. The same is true of some other trees. It is important 

 to have them on hardy roots in order to prev-ent root killing. 



Fig. 8.- 



-Tree gnawed by mice and the wounds bridged over with 

 cions. 



Heavy mulching about the roots of trees that are on tender 

 roots will often make them safe against winter injury. Deep 

 planting of trees on tender roots bring the roots deep in the 

 ground where they are not injured and the cion above will 

 generally send out hardy roots. As stated above, it is not un- 

 common to have the tender stocks on which trees are worked 

 killed out, and if the cion has rooted the effect is seen in a 

 weakened growth until a new root system has formed. If there 

 are no roots from the cion the tree dies. 



Protection from frost. Freezing affects different plants In 

 various ways. We can therefore divide plants into two classes: 



(a) Frost tender plants, such as the asparagus, ash, oak, 

 spruce and various other plants whose young foliage is easily 

 injured by severe frosts. 



(b) Frost hardy plants, such as the apple, peach, willow, 

 poplar and birch whose foliage is not destroyed by even a se- 

 vere frost. 



The flowers of many plants will stand a severe freeze with- 

 out Injury providing they are not open when it occurs. This is 



