260 ON PROPAGATION BY CUTTINGS. 



perature at which cuttings should be kept, that in which the respective 

 plants from which the cuttings are taken are found to produce shoots of 

 freest growth, is doubtless the best. The bottom heat should nearly equal, 

 but not exceed, that of the atmosphere. If the shoot has, however, been 

 much excited into growth by heat, in order to obtain the cutting (574), the 

 latter must have that heat kept up in its new situation, otherwise its 

 vegetation will be checked. For cuttings of all the difficult-rooting 

 greenhouse plants, the best heat for the soil is from 53 to 60 Fah. ; for 

 those of hothouse plants from 60 to 68 Fah., which should be as regular 

 as possible. This regularity is of great moment to insure the success of the 

 cuttings ; for if they are kept at a cooler temperature the greater part of 

 them form a callosity, but, for want of the necessary heat to assimilate the 

 deposited nourishing matter, do not form roots. The callosity continues to 

 grow in many species, such as Quercus, Hakea, and Protect, and often 

 becomes of so considerable a size, that it not only covers the face of the cut 

 with a thick layer, but also penetrates between the wood and the bark. 

 When this is the case, and the callus is not cut away, no roots are made, 

 and the cutting often remains several years without dying. Where the 

 propagation of house-plants by cuttings is carried on extensively, a pit or 

 house should be formed on purpose, in which there should be a bed of 

 gently fermenting matter, such as tan or leaves, or, what will in general be 

 found preferable, of sand, or coarsely-powdered charcoal, heated by the 

 vapour of hot water from below. Where dung beds are employed, great 

 care is necessary to prevent the exhalations rising from the dung to contami- 

 nate the air of the bed, which would destroy most cuttings. In general, 

 all cuttings whatever ought to be kept in what may be called the winter 

 temperature of the plant, for some time after they are planted, and only put 

 into their spring temperature when they have formed a callosity, and are 

 ready to grow. The cool period for cuttings put in without leaves, or with 

 leaves, but with ripened wood, will, of course, be much longer than those 

 put in with leaves, and in a growing state, such as geraniums, petunias, 

 dahlias, and even heaths. 



Cuttings of the plants in common cultivation in British gardens may be 

 classed as under : 



592. Cuttings of hardy deciduous trees and shrubs, such as the gooseberry, 

 currant, willow, poplar, &c., are easily rooted in the open garden, and the 

 same may be said of the vine and fig. As it is desirable that the gooseberry 

 and currant should not throw up suckers, and should have a clean stem, all 

 the buds are cut clean out, except three, or at most four, at the upper end 

 of the cutting. The cuttings are planted erect, about six inches deep, and 

 made quite firm by the dibber at their lower extremity. Cuttings of honey- 

 suckles, syringas, ampelopsis, art&nisza, atragene, atrlplex, baccharis, ber- 

 cherm'a, bignonta, calycanthus, ceanothus, chenopodum, clematis, China 

 roses, fig. 171, and the like, are rather more difficult to root, and succeed 

 best in a shady border and a sandy soil. 



593. Cuttings of hardy evergreens, such as the common laurel, Portugal 

 laurel, laurustinus, arborvitse, evergreen privet, and a few others, may be 

 rooted in common soil in the open garden ; being put in in autumn, and 

 remaining there a year. Cuttings of frupleureum, ftuxus, /uniperus, rhamnus, 

 holly, sweet bay, aucuba, c., require a shady border and a sandy soil. 

 They are put in in autumn, of ripened wood; but young wood of these and 



