428 JOURNAL OF FORESTRY 



CONCLUSIONS 



The results of detailed observations of the different species of euca- 

 lypts which passed through the freeze of 1913 lead to the following 

 conclusions as to their relative frost hardiness : 



1. Eucalyptus viminalis is the most frost-hardy species of the genus 

 that has so far been planted in southern California, followed by B. 

 polyanthema, B. gunii, B. bicolor, and B. regnans. 



2. Bucalyptus tereticornis, B. rostrata, and B. globulus form a second 

 group as regards frost resistance, but because of their usefulness they 

 are particularly deserving of attention from tree planters. 



. 3. Bucalyptus rudis, B. corymbosa, B. calophylla, B. cornuta, and 

 B. leucoxylon form a third group as regards frost resistance, and 

 should not be planted wherever there is the slightest danger of low 

 temperatures. 



4. Bucalyptus amygdalina and B. citriodora should not be planted 

 for park or ornamental purposes where there is a possibility of heavy 

 frost, because the appearance of these trees is greatly injured by the 

 development of sprouts along the stems and branches after a freeze. 



5. Wherever there is any likelihood of very low temperature, B. 

 crebra, B. gunii, B. polyanthema, and B. regnans are the best trees to 

 plant for ornamental and park purposes. 



6. After a season of low temperature, it is advisable to wait a rea- 

 sonable length of time before cutting down or pollarding eucalyptus; 

 otherwise trees may be mutilated that would resume their normal ap- 

 pearance in the course of time. 



7. When frost is expected, young nursery stock may often be saved 

 by covering the nursery with burlap and by smudging; young planta- 

 tions may be saved by covering the trees. 



