22 JIASDEVALLIA. 



vegetable matter ; hence, as regards potting, Masdevallias should be treated 

 as epiphytal orchids. They are, however, usually vigorous-rooting plants, 

 and require room for the development of their roots, to allow for which 

 pots of sufficient size should be used. The pots should be filled to two- 

 thirds of their depth with a drainage consisting of clean broken crocks 

 that have not been previously used for the same purpose, and the 

 remaining third with a compost of sphagnum moss and fibrous peat in 

 equal proportions ; into this compost the roots should be carefully placed, 

 the base of the plants being about on a level Avith the rim of the 

 pot, or at least not much above it. The best seasons for re-potting 

 Masdevallias are from the middle of January to the end of February, 

 and from the beginning of October to the middle of November. 



The temperature of the Masdevallia house should range throughout 

 the year as near as practicable between 10° and 18° C. (50° — 65° F.), 

 the night temperature descending about 5° F. lower than the day. In 

 sultry weather, such as sometimes occurs in July and August, Avhen 

 the external temperature is from 25° to 32° C. (77° — 90° F ), the 

 temperature of the house may be kept down by ventilation, by shading, 

 and by keeping its atmosphere well charged with moisture by frequently 

 Avatering the floors, stages and any surface from which water can 

 readily evaporate. Generally, by regulating the shading, ventilation, and 

 "damping down," as it is called by gardeners, during the summer, 

 according to external circumstances, the temperature of the house may 

 always be kept a few degrees lower than the external aii. 



In the humid climate in which the ]\lasdevallias live naturally, their 

 vegetation is at no period of the year interrupted, and hence, when 

 transferred to glass houses in this country, a constant sup])ly of water 

 is one of their most essential requirements. This is usually afforded 

 them in two ways — by maintaining a moist atmosphere in the house 

 in the manner described above, and by direct application of Avater to 

 the roots of the plants. The frequency Avith Avhich the damjiing down 

 should be done, and the qiiantity of Avater given at each Avatering, 

 must be determined by the needs and condition of the plants, and 

 according to the season of the year. Bearing in mind that Masdevallias 

 must never be alloAved to get dry at the roots, the cultivator Avill, by 

 inspection of the plants, be better able to judge hoAv much Avater should 

 be given to them, and hoAv often they require it, than by folloAving any 

 hard and fast rule. In Avinter, he may find that damping doAvn once 

 a day in the morning, and Avatering the roots once every four or five 

 days Avill be sufficient, or less in time of severe frost, but even then 

 the drying and exhausting effects of fire heat during prolonged cold 

 Aveather must be counteracted by damping doAAm and by Avatering the 

 plants. As the season advances, it may be found necessary to damp 

 doAvn both in the morning and in the evening, and to Avater the plants 

 once in three days or eveiy alternate day ; and in summer, damping 



