ON PROPAGATION BY CUTTINGS. 



257 



common trees and shrubs, which have been planted more than nine inches 

 or ten inches in depth. This is quite analogous to what takes place with seeds ; 

 when buried below a certain depth there is no sufficiency of either heat or air to 

 cause them to germinate ; and the same want of heat and air, 

 and probably excess of moisture, prevents roots from being 

 emitted from the lower ends of cuttings when inserted in the 

 soil to a much greater depth than that at which seeds would 

 vegetate. Hence all delicate cuttings, such as those of heaths, 

 diosmas, acacias (fig.l 69), epacrises, &c., succeed best when not 

 planted in sand more than from half an inchto an inch in depth. 

 Some heaths root best when the cuttmgs are not above three 

 quartei-s of an inch in length, with not more than a third of 

 that length in the soil. 



586. In planting cuttings it is of importance to make them 

 quite firm at their lower ends, by pressing the sand or soil to 

 them with the dibber used in planting them ; or in the case of 

 large cuttings, such as those of common laurel, which are 

 planted in trenches, by pressure with the foot. In the case 

 of Cape Heaths and such like cuttings planted in sand, the ^.^ ^ 

 dibber or pricker, which need not be larger than a knitting ting o} the young 

 needle, is taken in the right hand, while the cutting is held in ^"od v/Acdein 

 the left, and the hole being made the cutting is inserted, ^l^'pfaZ.^"^ 

 nearly as deep as the leaves have been clipped off, and the 



pricker is again applied to close the sand round it, as closely and compactly 

 as possible, without bruising the cutting. Large cuttings are planted pre- 

 cisely in the same manner, but with a larger dibber. Large cuttings of kinds 

 which are somewhat difficult to strike, when not planted in pure sand, are 

 made to touch and press against the bottom or sides of the pot, which is 

 found to facilitate their rooting — probably on the principle already men- 

 tioned (581). 



587. The distance at which cuttings are planted varies according to the size 

 of the cutting, its leaves (either on the cutting, or to be produced from its 

 buds), the season of the year, the length of time they require to root, and 

 other circumstances. The object is to root as many cuttings as practicable 

 in a limited space, and consequently to plant them as close together as can 

 be done without incurring the risk of rotting or damping them off. Keeping 

 these objects in view, it is obvious that cuttings which strike in a short time 

 during spring or summer may be planted closer than those which require a 

 longer period, or are put in in autumn or winter; and that short cuttings, 

 such as those of heaths, may always be placed closer together than long 

 cuttings. All cuttings whatever that are planted with the leaves on, require 

 to be immediately well watered, in order to settle the soil about them ; and 

 all those that are in a growing succulent state, and are at all difficult to 

 strike, should be immediately covered with a hand- glass or bell-glass ; for, 

 though the cutting receives as much moisture through the face of the cut as 

 it loses in ordinary circumstances by evaporation, yet no sooner is it placed 

 in very dry air or in a draught, or exposed to the sun's rays, than a dispro- 

 portion takes place between the demand and supply. When this is the 

 case, more watery particles are lost through evaporation, than are raised in 

 the body of the wood, which is very easily perceived in large soft leaved 

 cuttings. On this account plant structures are required, in which the outer . 



