396 SEEDING AND PLANTING 



most frequently propagated in this manner are black locust, 

 Ailanthus, silver poplar, and many surface-rooted shrubs. The 

 formation of root suckers can be greatly stimulated by uncovering 

 the surface roots of the parent tree, cutting incisions through the 

 bark and later covering them again. 



When the sucker is from 1 to 3 years old it is prepared for 

 removal from the parent tree by cutting off the root from 6 to 

 10 inches from the shoot at either side. This should be done 

 at least 1 year before the sucker is removed for setting in the 

 nursery or plantation./ If removed without this preliminary treat- 

 ment it is almost invariably without fibrous roots and consequently 

 of little or no value for field planting. The trees produced from 

 root suckers are usually inferior to those grown from seed. A 

 portion of the root of the mother tree remains with the sucker 

 and becomes overgrown. Trees grown from root suckers are 

 likely to develop rotten heart. 



41. PLANTING ROOT CUTTINGS 



Pieces of well-developed roots from 6 to 10 inches long and \ 

 to 1 inch thick may be used to propagate a number of broadleaved 

 species. The cuttings are made in autumn or winter and planted 

 directly or wrapped in moss and stored in a cool, moist cellar. 

 The process of storing develops a callus at the cut ends and stimu- 

 lates the production of buds. Root cuttings are never set directly 

 in the field but are set in the nursery for 1 or more years or 

 until they are sufficiently large for planting in the open field. 

 They are usually placed in V-shaped trenches in an upright posi- 

 tion and completely covered with soil well pressed down. The 

 end of the cutting from nearest the stump of the parent tree should 

 be uppermost. 



When root cuttings are stored over winter they are set in 

 the nursery in the spring just before vegetation starts. Many 

 woody species of the families Rosacece and Oleacece may be 

 freely propagated by root cuttings. This method is most service- 

 able in horticulture. It is rarely used in propagating stock for 

 forest planting. 



42. PLANTING SHOOT CUTTINGS 



Shoot cuttings are pieces of branches which are placed in the 

 soil to develop roots. Before the development of roots their only 

 means of absorption from the soil is through the end of the cut- 



