ON PLANT PROPAGATION. 



953 



Fig. 620. — Layering by Piercing or Notching. 



in the illustration. Pegs are used to fix layers, and a light 

 soil employed to cover the whole. 



Insertion of the Growing Point. — This is another excellent 

 method useful when 

 roots are found 

 already attached to 

 the layer, as is 

 often seen in Cur- 

 rants and Goose- 

 berries. When 

 placed in a well- 

 manured soil at the 

 beginning of the 

 summer, these 

 layers will be found 



covered with roots by the autumn, and already possessing a 

 growing bud. This fact is noticeable in several other shrubs. 



Layering above the Ground (also known as Circumposition). 

 — When the branches to be layered are too far off the ground to 

 be bent down, this principle is applied in several ways. Small 

 boxes are used, or a flower-pot is cut into two pieces, 

 and these receptacles are fastened together around the 

 portion to be operated on, being fixed in such a way as to 

 prevent them from moving ; long stakes, w^ell secured in the 

 ground, and to which boxes or pots may be attached, are 

 sufficient. Instead of cutting the pot into two pieces, a section 

 could be taken out of one side equivalent to the size of the 

 branch to be propagated. Then the stem or branch may be easily 

 fixed in the middle of the pot, and a piece of slate or glass used 

 to close it up. The selected branches must be treated by the 

 tongueing or ringing method, and the boxes or pots afterwards 

 filled up with a very light soil, corresponding in some respects 

 with that in which the parent plant is growing. The whole is 

 generally covered w^th moss, which is kept saturated to prevent 

 the soil from drying. When the branches begin to root, a partial 

 incision is made in the stem just below the receptacle, thus 

 enabling the sap to continue flowing ; but as it cannot return it 

 flows into the young roots. After the layered portion has emitted 

 enough roots, it is entirely removed.- 



This method of propagation is often applied to Cordylines 

 (Dracaenas). Some plants, such as Crotons and the above-men- 

 tioned, which sometimes reach a large size and lose their bottom 

 leaves, can by this means be reduced to the dimensions required. 



Layering Underground. — In this process the layered part 

 which is to develop the roots is put in contact with the earth. 

 If the branches are flexible, they are bent downwards in a place 

 previously prepared with a lighter soil, according to the nature 

 of the subject. 



