Issued January 19, 1907. 



United States Department of Agriculture, 



FOREST SERVICE Circular 57. 



GIFFORD PINCHOT, Forester. 



WANTING ^^^^.^ 

 JACK PINE (Pinus divaricata). 



FORM AND SIZE. 



Jack pine usually attains a height of from 30 to 50 feet and a 

 diameter of from 8 to 12 inches. Under favorable conditions a 

 height of 90 feet and a diameter of 2 feet may be reached. It has 

 a fairly straight and symmetrical stem, and when grown free a 

 low, full crown. In close stands the crown is narrow and covers 

 only the upper part of the tree. The needles are 1 to 1J inches long 

 and grow in pairs bound by a short sheath. 



RANGE. 



The natural range of jack pine is along the northern border of the 

 United States, from eastern Maine to Minnesota. In the United 

 States it is commonest in northern Michigan, Wisconsin, and Min- 

 nesota, where it occupies great areas of barrens or is found with 

 red pine or with stunted oaks and other broadleaf species. 



The tree is recommended for planting in the North Central States 

 where the soil is poor but contains moisture not far below the 

 surface. 



SILVICAL QUALITIE^. 



Jack pine is a very hardy tree, and is suited to sterile, sandy 

 soils. It can be planted with a good prospect of success where few 

 other trees grow, provided ground water is not too far below the 

 surface. It will withstand considerable drought, and is rarely 

 injured by frost. It is intolerant of shade at all ages, and there- 

 fore not well adapted for mixed plantations. 



It is one of the most rapid-growing pines, but is comparatively 

 short lived, reaching maturity in about sixty years. 



Jack pine suffers little from insects or disease. Wind will some- 

 times overthrow the trees, especially where the roots have been 

 forced close to the surface of the ground by excess of moisture. 



ECONOMIC USES. 



The wood is light, soft, coarse grained, moderately strong, and 

 moderately durable. It makes good coarse lumber, and, when 

 chemically treated, very satisfactory posts and ties. In most of its 

 qualities it compares with the loblolly pine of the Southeast. It is 

 somewhat inferior to red (Norway) pine and western yellow pine. 

 Jack pine is a good tree for windbreaks and shelterbelts, and for 

 10762 No. 5707 M 



