of an inch, but usually it is much less. Hackberry is sometimes found 

 in situations so unfavorable that fifteen years or more are required 

 for an inch of diameter growth. Its period of most rapid growth is 

 between the twentieth and fortieth years. It reaches an age of from 

 one hundred and fifty to two hundred years. 



The hackberry is generally a healthy tree, though often its leaves 

 are covered with insect galls. In case harmful insects appear in 

 threatening numbers, specimens, accompanied by a full description of 

 their depredations, should be sent to the Department of Agriculture 

 for identification and suggestions for their destruction or control. 



ECONOMIC USE. 



The wood of the hackberry is of medium weight, hardness, and 

 strength and is rather elastic. It makes excellent fuel, almost equal- 

 ing hickory, and is used also in the manufacture of cheap furniture. 

 The technical qualities of hackberry wood resemble those of elm and 

 \vhite ash, and it is occasionally used as a substitute for them. It is 

 not durable in contact with the soil, and, like hickory, when used 

 unpeeled above ground is likely to become worm-eaten. When peeled 

 and properly seasoned hackberry poles serve many useful purposes 

 on the farm. 



It is chiefly as a living tree in regions where trees of any kind are 

 highly prized that the hackberry is of greatest economic value. In 

 mixture it serves a good purpose by shading the ground and furnish- 

 ing litter to enrich the soil. 



METHODS OF PROPAGATION. 



The hackberry is usually propagated from seeds. When a seedling 

 has its top killed it readily sprouts from the root, but large 'trees 

 rarely sprout after cutting. 



The hackberry bears seeds abundantly. The fruit is a bluish- 

 brown drupe about the size of a pea. The thin fleshy layer which 

 covers the stone shrivels and dries and need not be removed before 

 planting. The seeds ripen in the fall and may be sown at once. If 

 spring sowing is preferred the seeds should be stratified in sand and 

 kept buried over winter in a well-drained place out of doors. To fill 

 a box with alternating layers of sand and seeds and sink even with 

 the surface of the ground is a good method of stratification. When 

 filled the box should be covered with a wire screen or boards to keep 

 out mice and then mulched with leaves or straw to protect the seeds 

 from sudden changes in temperature. 



The seeds should be sown in drills in good, rich soil, covered not 

 more than half an inch deep, and the soil firmly pressed down upon 

 them. Since hackberry seedlings grow only from 6 to 12 inches 



[Cir. 75] 



