A HANDBOOK FOR EUCALYPTUS PLANTERS. 9 



groves have sprouted up vigorously after the fourth and fifth cutting, 

 and seedling trees over thirty years old sprout after cutting as thriftily 

 as young trees. Indeed, it is almost impossible to kill the stumps of old 

 trees or to prevent the sprouting of old roots left in the ground after 

 the stumps have been grubbed out. 



Seed Reproduction. Since natural regeneration is not practiced, the 

 natural seeding of eucalypts is of little commercial importance. Seed 

 is produced abundantly by all the eucalypts introduced into California. 

 The fruit generally remains on the trees, unopened, until the fall of 

 the seed cases to the ground. Wind dissemination plays no part in the 

 extension of Eucalyptus, and as the seeds are not eaten by birds, the 

 seedlings always occur beneath or very near the parent tree. 



GENERAL REQUIREMENTS. 



Every species makes definite ecological demands upon its habitat. 

 The optimum development of a species is contingent upon the fulfill- 

 ment of its requirements. It generally happens, however, that the 

 demands of a species are not inflexible, and the species will survive 

 if its requirements are but partially met. For example, a species will 

 survive and grow indifferently, if it receives less food or light than it 

 requires for best development. In the case of temperature much 

 depends upon the age and condition of the tree species at the time its 

 normal temperature range is crossed. If it is thriving and the tempera- 

 ture change comes gradually it will frequently withstand the shock 

 without injury. Under less favorable conditions it will not recover. 

 Except upon temperature the demands of eucalypts are fairly flexible. 

 Their thermal demands, however, must be met. Whenever Eucalyptus 

 planting is undertaken outside the thermal range of the species used 

 some loss must be expected. Where only small plantations are made 

 a risk is generally warranted. But where extensive commercial planta- 

 tions, involving heavy expense, are made, they should lie within the 

 thermal range of the species used. Since this circular deals with the 

 commercial production of eucalypts, the planting of any species will 

 not be recommended outside its thermal range. It is probable that most 

 of the species treated will grow, indifferently at least, considerably out- 

 side of the range where their planting will be advised. 



Soil. Practically, all the eucalypts grow best on a deep, fertile, well- 

 drained, loam soil. But, as more valuable crops likewise develop most 

 successfully there, the necessity arises of finding similar or poorer 

 classes of land, which, on account of inaccessibility, or roughness. 



