With the diminution of the Avhite-pine supply yellow poplar is 

 much used in its place. The lumbermen recognize two kinds of pop- 

 lar timber, white and yellow. The difference in color is caused mainly 

 by the difference in site conditions, since trees grown on dry, grav- 

 elly soil produce a wood that is lighter in color and harder to work, 

 and is called " white poplar " or " hickory poplar." The " yellow 

 poplar " is grown on rich alluvial or limestone soil, and has a rich yel- 

 low heartwood which is highly prized because of its fine grain and 

 easy working qualities. 



Yellow poplar is an excellent tree for shade and ornament, and is 

 especially suited to these purposes in cities where bituminous coal is 

 burned. Forest planting of this species for economic purposes has 

 never been attempted, but it should prove profitable wherever natural 

 conditions are favorable, because of the rapid growth of the tree, its 

 large size and splended form at maturity, and the value of the Avood. 



PROPAGATION. 



Yellow poplar reproduces itself almost entirely by seed. Its ability 

 to sprout from the stump is very limited, and can not be depended 

 upon. 



Seeds are produced abundantly nearly every year, though only from 

 5 to 10 per cent are fertile. They are borne in a cone-like fruit 1 to 2 

 inches long. Young trees are likely to produce seed which is abso- 

 lutely worthless, and on older trees good seed is found only in the cen- 

 ters of the cones on the highest limbs-. Seed should be collected in 

 the fall when mature, and may be sown at once or stratified in sand 

 for spring planting. It is advisable to plant in the fall; germina- 

 tion will then take place the following spring. If sown in the spring 

 the seeds have a tendency to lie in the ground a year before germi- 

 nating. 



The use of nursery-grown seedlings or transplants is recommended 

 for establishing plantations of yellow poplar. Sowing in the per- 

 manent site, however, is occasionally successful. 



To grow nursery stock the seed should be sown thickly in drills, in 

 light, rich, sandy soil and covered to a depth of one-half inch. It is 

 especially important that the soil be kept evenly moist. More water 

 should be supplied during the germinating period than later. It 

 may be found necessary to provide partial protection on hot, sunny 

 days during the first season, especially in the South. Seedlings may 

 grow in the nursery for one or two years, but should not remain 

 longer, because of the strongly developed taproot and few lateral 

 roots, which make transplanting difficult. Transplanting 1-year-old 

 seedlings into nursery rows will stimulate the development of fibrous 

 roots and insure vigorous plants, but this operation is not generally 



[Cir. 93] 



