390 



HENDERSON'S HANDBOOK OF PLANTS. 



PRO 



propagating at a low temperature is ca- 

 pable of producing a larger number of 

 plants during the season than at a high 

 temperature and in a close atmosphere. 

 There need be no failures; and it has the 

 important advantage of producing a 

 healthy stock, which the close or high 

 temperature system would fail to do in 

 the case of many plants. We have often 

 heard propagators boasting of rooting 

 cuttings in five days. We are well aAvare 

 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 tem- 

 perature, which at all times causes the 

 plants to draw up slender, and thus im- 

 pairs their vigor. 



Permitting a moderate circulation of 

 air in the propagating house tends to 

 prevent the germination of that spider- 

 web-like substance, which, for want of a 

 better term, is known among gardeners 

 as the "fungus of the cutting bench." 

 Every one who has had any experience 

 in propagating knows the baneful effects 

 of this; how that, in one night, it will 

 often sweep off thousands of cuttings that 

 a few hours before were in healthful vig- 

 or. But this dangerous enemy of the 

 propagator requires, like vegetation of 

 higher grades, conditions suitable to its 

 development, 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 regulation of fire heat, to keep 

 the atmosphere of the house so that it 

 shall not exceed 60 degrees. This, of 

 course, is not practicable when the out- 

 side temperature in the shade is above 

 60 degrees; but the temperature can be 

 reduced considerably by dashing water 



PRO 



on the pathways and other parts of the 

 house. It is rarely, however, that the 

 outside temperature ever exceeds 60 de- 

 grees in the shade for any length of time 

 in the district 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 middle of September, 

 operations in propagating may again be- 

 gin. 



The temperature is prevented from ris- 

 ing in the house in various ways, some 

 using canvas, or bast-matting, or paint- 

 ing the glass with lime or whitewash. 

 We find the best and most 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 un- 

 rolled, and give an ever-varying modified 

 shade, sufficiently cooling to the house, 

 yet not darkening the cutting enough to 

 impair its vigor. These are not un- 

 rolled in the morning until the tempera- 

 ture 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 cut- 

 tings receive as much light as they will 

 bear without becoming wilted. The time 

 required by cuttings to root varies from 

 eight to twenty days, according to the va- 

 riety, condition of the cutting, and tem- 

 perature. Verbenas, Fuchsias, or Helio- 

 tropes, put in in proper condition, and 

 kept without ever being allowed to wilt, 

 will root, in an average bottom heat of 65 

 degrees, in eight days, while Roses, Pe- 

 largoniums, or Petunias will take at least 

 double that time under the same condi- 

 tions. 



