96 ELEMENTARY FORESTRY. 



before planting. This is most easily accomplished by means 

 of w r hat is called the "solar pit," which owes its success to 

 the fact that cuttings root first at the warmer end. It is made 

 and used as follows: The bundles of cuttings are heeled in as 

 recommended. In the spring they are taken out and buried 

 close together with the butt ends uppermost in a warm sunny 

 spot and covered with about six inches of soil. A hotbed 

 frame with sash is then put over the spot to warm the soil. 



Sometimes instead of using sash 

 the soil over the cuttings is cov- 

 ered with a foot or more of fer- 

 menting manure. In either case 

 the soil is warmed and the for- 

 mation of roots encouraged. In 



bowing btm4^oTrattig> using the solar pit the rooting 

 in place under glass. process should not be carried so 



far as to permit roots to show plainly, as they are liable to be 

 broken off in planting out, but the cuttings should be planted 

 out as soon as they show signs of healing over on the butt 

 end. This healing over process is called callousing and in 

 many plants necessarily precedes the formation of roots. 



LAYERS. 



Layers are portions of the branches of trees, shrubs or 

 vines which are covered with earth without being separated 

 from the parent plant and there take root and grow. These 

 are cut off from the main plant in autumn or spring and form 

 new plants. Almost all trees and other plants can be rooted 

 in this way, but while some root very easily others require so 

 long a time to do so as to make it impracticable with them. 



The growing of trees from layers is seldom practiced in 

 this country, but in some European nurseries it is a common 

 means by' which to increase special varieties of trees. For 

 this purpose what is commonly known as mound layering is 

 often used. This consists simply of drawing the soil up 

 around the sprouts that come from -the stump of a tree, cover- 

 ing the base of them about a foot in depth. It may be done 

 at anytime of the year after the sprouts are two or more feet 

 high, but preferably in the spring. After the sprouts have 



