12 STATE BOARD OF FORESTRY. 



PLANTING REGIONS. 



The area within which the timber eucalypts may be successfully 

 propagated has been broadly defined as that bounded by the frost line. 

 The manna and gray gums may be safely planted when the temperature 

 does not drop below 22 F. This area is shown, approximately, by the 

 accompanying isothermal map. Commercial planting outside the 22 F. 

 isotherms is not recommended for any species, nor outside the 26 F. 

 and 28 F. isotherms for blue and sugar gums, respectively. 



For successful growth the requirements of eucalypts for soil and 

 moisture are but little more elastic than for temperature. It is unwise 

 to set high-priced seedlings on shallow soil or where the water table 

 is far below the surface. Planters should not forget that the rapid 

 growth and proper development of eucalypts is contingent on their 

 food supply rather than on any inherent quality. Where the water 

 table is accessible at not more than 25 feet below the surface, good 

 growth may be expected. 



CHOICE OF SPECIES. 



Generally speaking, the blue and sugar gums should be chosen for 

 planting within their thermal ranges. Outside these the red, gray and 

 manna gums must be considered as the leading species; 



Whenever the selection of species lies between blue and sugar gum, 

 the kind of product desired and the amount of soil moisture present 

 must determine the choice. If firewood, piles, or dimension stuff is 

 desired, the blue gum should be selected, especially if there is no marked 

 deficiency of soil moisture. If poles, ties or a wood of unusual durability 

 and strength is desired the sugar gum should be chosen, particularly if 

 the situation is rather arid. The sugar gum is the more drought-resist- 

 ing, but the blue gum is the more rapid-growing. 



Outside the planting range of the blue and sugar gums the red gum 

 commends itself, owing to its frost-hardiness and the durability of its 

 timber. In frosty or swampy locations it should receive first preference. 

 The uses of its product are limited, however, by the fact that it is 

 inclined to a crooked, branchy form. It is of rapid growth and furnishes 

 a product which is very durable in contact with the soil. 



The gray gum is equally rapid in growth, but is somewhat less frost- 

 hardy than the red. It grows in good form, especially in plantations, 

 and furnishes a very durable timber. 



Manna gum grows very rapidly, but it is hardly worthy of considera- 

 tion, since it is but slightly more frost-hardy than the sugar and blue 

 gums, while its timber is inferior to that of either species. 



Lemon gum is probably more valuable for ornamental than for 

 economic planting. Its rate of growth is about equal to that of red 



