II 



CLIMATOLOGY 



The principal horticultural fact in the climatology 

 of the peach is the relative tenderness of the tree 

 toward cold. The peach is generally rated as dis- 

 tinctly less hardy than the apple tree, though com- 

 mercially considered this difference is less than the 

 popular imagination has painted it. Practically 

 speaking, the northern limit of commercial peach 

 growing does not lie so very far south of the north- 

 ern limit of commercial apple production. Still, 

 it does lie distinctly to the south, and the peach tree 

 is obviously more tender during severe winters than 

 the apple. 



Twenty degrees below zero may be taken as the 

 practical limit of cold resistance for the peach. 

 When temperatures run lower the peach trees are 

 always in danger and usually sustain greater or less 

 damage. The amount of this damage is influenced 

 by many collateral circumstances, chiefly the fol- 

 lowing: 



1. Duration of the cold weather. Long-continued 

 low temperatures do greater injury than those which 

 last for only an hour or two. 



2. Varieties. Some varieties are considerably 

 hardier than others. 



3. Condition of trees. Vigorous, healthy, well- 

 grown trees will stand a good deal of freezing, while 

 weak, starved trees and those which have been al- 

 lowed to overbear will die outright in very mod- 

 erate weather. It has often been claimed that peach 

 trees easily make a too vigorous growth, and that In 



12 



