56 



HORTICULTURE FOR SCHOOLS 



otherwise it is treated the same as in simple layering. Com- 

 pound layering is much used with vines. 



76. Continuous layering (Fig. 30), in which a considerable 

 length of the stem is covered with soil, leaving the tip exposed, 



is used only in cases of 

 a few plants such as 

 the osier and snowball, 

 which produce roots 

 readily from the buds. 

 77. Trench layering 

 is used in propagating 



certain varieties of grapes and other vines which do not de- 

 velop roots readily when layered in the ordinary way. The 

 stem is pegged down in a shallow trench until shoots and 

 roots start at the nodes. Roots can be induced to develop 

 quickly by wounding the under side of the nodes. A little 

 soil is finally placed in the trench. 



78. Mound layering is used in propagating currants, 

 gooseberries, and other plants hav- 

 ing stiff stems which are difficult 



to bend over and layer by the 

 usual methods. The stems are 

 commonly wounded at the base 

 and mounded up with soil 

 (Fig. 31). In commercial work, 

 the plant is generally cut back 

 during the preceding season so 

 that many new shoots are 

 forced out to give a large number of shoots for layering. 



79. Chinese or pot layering is practiced with certain 

 classes of shrubs and trees having stems which cannot be 

 bent to the ground readily. Among these are rubber plants, 

 crotons, and oleanders. Portions of the stems are wounded 

 and bound in sphagnum moss. Sometimes specially con- 

 structed divided earthen pots are placed on the wounded 



FIG. 31. Mound layer. 



