August i, 1882.] 



THE TROPICAL AGRICULTURIST. 



119 



Propagation of Plants hy Cuttings.— As now understood, 

 this is a simple matter. Formerly no operation in liorti- 

 culture was more befogged by ignorant pretenders, who, in 

 writing or speaking on the subject, warped the operation 

 with troublesome conditions as to discourage not only 

 amateurs in horticultiure but inexperienced professional 

 gardeners as well. 



One of the first necessary conditions in the propag- 

 ation of plants by cutting.s is that the plant from wliich 

 the cutting or sUp is taken must be in vigorous health. 

 If weak or tainted by disease, failure is almost certain to 

 result. If, for example, we wish to root cuttings of green- 

 house or bedding plants, such as Bonvardias, Chrt/santlie- 

 viiims, Fuchsias^ Geranittnis, Heliotropes, Salvias, J'erbenas, 

 etc., one of the best guides to the proper conJitton is 

 when the cutting breaks or snaps clean off instead of bend- 

 ing or kneeing; if it snaps off so as to break, then it 

 is in the condition to root freely ; if it bends, it is too 

 old, and, though it will root, it will root much slower, 

 and make a weaker plant than the sUp that snaps off on 

 being bent. "With exceptions so few, and those of so 

 little importance that it is hardly worth while to aUude 

 to them, cuttings of all kinds root freely from sUps 

 taken from the yoiiiuj icood, that is, tlie succulent gi'owth, 

 before it gets hardened, and when in the condition indic- 

 ated by the " snapping test," as it is called. "We believe 

 we were the first to call attention to tliis valuable test 

 of the condition of the cutting (snapping) in our work, 

 " Practical Floriculture," fir.st published in 1868. A very 

 general idea is ciu-rent that cuttings must be cut at 

 or below an eye or joint. The practice of tliis sys- 

 tem leads undoubtedly to many cases of failure ; not that 

 the cutting at or below a joint either binders or assists 

 the formation of roots ; but from the fact that, when a 

 slip is cut at a joint, the shoot often has become too 

 hard at that pDint, while half an inch higher up or above 

 the joint the proper condition will be found. We know 

 that it will root even when in the too hard condition, 

 but the roots emitted will be hard and slender, and, as 

 a consequence, will not be likely to make a plant of the 

 same vigor as that made from the cuttiag in the proper 

 state ; besides, as the hard cutting takes double the time 

 to root, its chances of damping oft" from unfavorable 

 atmospheric conditions are thus increased. With these in- 

 structions for the proper state of the cutting, we now 

 proceed to describe the medium wherein it is to be placed, 

 and the conditions of temperature, moisture, etc. If these 

 are strictly followed, failin-e is an impossibility ; for the 

 laws governing the root of a slip aas certain as those 

 governing the germination of a seed. In our own practice, 

 when these conditions are strictly followed, failure is unkown. 



The most proper condition of temperatiu-e to root cut- 

 tings of the great majority of greenhouse and bedding 

 plants is 65 degrees of bottom heat, indicated by a thermo- 

 meter plunged in the sand of the bench, and an atmo- 

 spheric temperature of 15 degrees less. A range of 10 de- 

 grees may be allowed, that is, 5 degrees lower or 5 degrees 

 higher, but the nearer the heat of the sand can be kept 

 to 65 degrees, and that of the rest of the house to 50 

 degrees, the more perfect the success will be. 



Sand is the best medium in which to place cuttings ; 

 color or texture is of no special importance. "What we 

 use is the ordinary sand used by builders ; this is laid 

 on the hotbed or bench of the greenhouse to the depth 

 of about three inches and firmly packed down. When "bot- 

 tom heat " is wanted, the flue or pipes under the bench 

 of the greenhouse are boarded in, so that the heat strikes 

 the bottom of the bench, thus raising the temperature 

 in the sand. 



From the time the cuttings are inserted in the sand 

 until they are rooted, they should never be allowed to 

 get dry : in fact, our practice is to keep the .sand soaked 

 with water, the cutting bench being watered copiously every 

 morning, and often, when the atmosphere is dry, again 

 in the evening. Kept thus .saturated, there is less chance 

 of the cutting getting wilted, either by heat from the sun 

 or from fire heat ; for, if a cutting once gets wilted, its 

 juices are expended, and it becomes in the condition of 

 a hard cutting, in the condition in which, when bent, it 

 will not snap nor break, which has already been de- 

 scribed. To avoid this wilting or Uagging of the cutting, 

 every means that will suggest itsell to fhe propagator 



is to be used. Oui- practice is to shade and ventilate in 

 the propagating house or hotbed just as soon in the 

 forenoon as the action of the sun's rays on the glass 

 raises the temperatiu-e of the house to C5 degrees or 70 

 degi-ees. This practice of ventilating the propagating house 

 or hotbed is, we are aware, not in very common use ; many 

 contending that the place where the propagating is done 

 should at all times be kept close. We have tried both 

 methods long enough and extensively enough to satisfy us 

 beyond all question, that ventilating and propagating at a 

 low teraperatm-e is capable of producing a larger num- 

 ber of plants during the season than at a high temp- 

 erature and in a close atmosphere. There need be no 

 failures, and it has the important advantage of produc- 

 ing healthy stock, which the close or high temperature 

 system would fail to do iu the case of many plants. We 

 have often heard propagators boasting of rooting cuttings 

 in five days. We are well aware that this may be done, 

 but we are also aware that it is often done in damp 

 and cloudy weather at the risk of the whole crop, and 

 it must be done at a high temperature, which at all 

 times causes the plants to draw up slender, and thus im- 

 pairs then- vigor. 



Permitting a moderate circulation of air in the propag- 

 ating house tends to prevent the germination of that 

 spider-web-like substance, wliich, for want of a better term . 

 is known among gardeners as the "fungus of the cutting' 

 bench." Everyone who has had any experience in pro- 

 pagating knows the baneful effects of tliis : how that, in 

 one night, it will often sweep off ' thousands of cuttings 

 that a few hours before were in healthful vigor. But 

 this dangerous enemy of the propagator requires, like 

 vegetation of higher grades, contUtions suitable to its develop- 

 ment, which evidently are a calm atmosphere and a 

 temperature above 55 or 60 degrees. Hence, to avoid this 

 pest, we make every effort, by shading, airing, and regul- 

 ation of fire heat, to keep tlie atmosphere of the house 

 so that it shall not exceed 60 degrees. This, of course 

 is not practicable when the outside temperature in the 

 shade is above 60 degrees ; but the temperatiu-e can be 

 reduced considerably by dashing water on the pathways 

 and other parts of the house. It is rarely, however 

 that the outside temperature ever exceeds 60 degrees 

 iu the shade for any length of time in the dis- 

 trict of New York before the middle of May, and 

 all propagating had better be finished previous to that 

 time, unless of tropical plants. In the fall months, about 

 the miildle of SeptemVier, operations in propagating may 

 again begin. 



Tlie temperature is prevented from rising in the house 

 in various ways, some using canvas, or bast-matting, or 

 painting the glass with hnie or whitewash. We find the 

 best and mo.st convenient shading to be that formed by 

 flexible screens made of common lath, planed and attached 

 together like Venetian blinds, the laths being an inch or 

 so apart; these can be quickly rolled or unrolled, and 

 give an ever-varying moihfied shape, .sufficiently cooling 

 to the house, yet not darkening the cutting enough to 

 impair its vigor. These are not unroUed iu the morning 

 until the temperature inside indicates it to be necessary, 

 and are rolled up in the afternoon as soon as the sun 

 ceases to shine on the glass, for it is of the utmost 

 importance that the cuttings receive as much light as they 

 mil bear without becoming wilted. The time reqiured by 

 cuttings to root varies from eight to twenty days, accord- 

 ing to the variety, condition of the cutting, and temp- 

 erature. Verbenas, Fuchsias, or Heliotropes, put in in 

 proper condition, and kept without ever being allowed 

 to wilt, will root, in an average bottom heat of 65 de- 

 grees, in eight days, while roses, pelargoniums, or 

 petunias, will take at least double that time under the 

 same conditions. 



It is best to pot off the cuttings at once when rooted, no 

 matter how small the roots may be ; half an inch is a much 

 better length for them to be when potted than two inches, 

 and the operation is much quicker performed when the roots 

 are short than when long. But the main erils of delaying the 

 potting off of cuttings are that, when left too long', the 

 cuttings grow up weak and spindling, the roots become 

 hard, and do not take as quickly to the pot. The same 

 care is required in shading and watering after potting, 

 nearly, as in the cutting bench ; for uo matter how care- 



