PROrAGATION. 



S73 



and, if excessive, finally destroy the cutting. We 

 know that a great many cuttings emit roots freely 

 and comparatively quickly when placed with their 

 hases in water, and this method is often resorted to 

 for the increase of many plants. Draca3nas, Cro- 

 tons, Nepenthes, Yuccas, Verbenas, Lobelias, and a 

 Iiost of other plants may be propagated by this 

 means ; and yet, notwithstanding this, an excess of 

 moisture in soil containing cuttings of these plants 

 often proves fatal to them. From this it Avill be 

 evident that if soil is employed for the j)ropagation 

 of cTittings, it must be well drained, and must be 

 kept moist without being allowed to become stag- 

 nant. Sand is perhaps the best and safest medium 

 for cuttings to form roots in, because it not only 

 does not contain the gases which in soil are a source 

 oi danger to cuttings, 

 but it prevents exces- 

 sive moisture from ac- 

 cumulating about them, 

 and maintains a sweet 

 and moist condition. 

 Hence it is that many 

 of the most successful 

 propagators use soil 

 only in the lower por- 

 tion of the cutting-pot, 

 the upper being filled 

 with clean sand. It is 

 not known that soil 

 is essential to the for- 

 mation of roots on 



cuttings ; moisture alone being required to maintain 

 the cuttings in health, and supply the only food the 

 cutting is capable of absorbing. Indeed, it might 

 rather be said that the cuttings do not even absorb 

 moisture until they have formed roots, if the sur- 

 rounding atmosphere is sufficiently saturated to 

 prevent the moisture contained in the cutting from 

 ovaporating through perspiration. This is to be 

 seen in the fact of many cuttings forming roots even 

 when the whole of them is exposed to the air, if the 

 moisture of the atmosphere is sufficient to keep the 

 cuttings from perspiring, the effect of which is what 

 in garden phraseology is termed " flagging." The 

 maintenance of the proper condition of the soil and 

 atmosphere as regards moisture is an important 

 point in the art of propagation ; hence the use of 

 bell-glasses, propagating-cases, and such-like ap- 

 pliances, whose special purpose is the prevention of 

 perspiration in the cuttings. Saturation point for 

 the atmosphere, and moistness without stagnation 

 in the soil, are necessary for the successful propa- 

 gation of most plants, the only exceptions perhaps 

 being those of a succulent, tough-skinned nature. 

 Hea.t is an important factor in the multiplication 



Fig. ll.-Cuttmg of 

 Pelargonium. 



of plants. It may be taken as an unvarying rule 

 that all plants require for their propagation a higher 

 temperatui'e than they enjoy natuially. In many 

 cases it is found that a very high temperature indeed 

 may be used for cuttings of many plants, and if care- 

 fully applied this excessive heat may be productive 

 of extraordinary success. For the propagation of 

 many of our hardy plants a tropical heat is often re- 

 sorted to, and as the effect of this is the formation of 

 roots in a very short time, and an excitement into 

 immediate growth, a great saving of time is thus 

 secured. But as we are now dealing more especially 

 with in-door plants, it may be stated that cuttings of 

 the whole of these strike freely in a temperature 

 about 10° higher than the plants themselves require. 

 Bottom-heat may be employed for cuttings of soft- 

 wooded plants from the 

 first, as the process of 

 callusing and forming- 

 roots is in their case 

 much more rapid than 

 in the case of hard- 

 wooded plants. The 

 temperature of the soil 

 or sand in which the 

 cuttings are planted 

 should exceed by a few 

 degrees that of the at- 

 mosphere surroimding 

 them. A wide difference 

 between these is almost 

 sure to excite the cut- 

 tings into weak and premature growth, which, being 

 unsupported by roots, soon rots, and the whole cut- 

 ting perishes. Shade from bright sunlight is neces- 

 sary for the safety of soft- wooded cuttings, but it is 

 not advisable to shade more than prevents the 

 sun's rays from reaching the cuttings, as excessive 

 shade weakens the foliage, and renders the fresh 

 growth so soft that the cutting is apt to damp off. 



These general principles mav be apiDlied to the 

 propagation of all soft-wooded plants. The limits of 

 our space forbid us to do more than point out the 

 principles of the methods practised for the multipli- 

 cation of the thousands of plants which come under 

 this heading. As has already been pointed out, 

 spring is the most favourable time for operations with 

 soft- wooded plants, although their natm-e is such as 

 admits of their pi'opagation at any time of the year. 

 Dracaenas, Crotons, Begonias, Hibiscus, and such- 

 like strong and free-growing subjects, may be pro- 

 pagated by means of large pieces, which when rooted 

 are good plants at once. Bouvardias may be taken 

 as representative of that class of plants the wood of 

 which is fairly hard when ripened, but young shoots 

 of which are soft and sappy. Of these, the portions 



Fig. 12.— Cutting of 

 Bouvardia. 



