GREENHOUSE PLANTS. 



148 



GREENHOUSE PLANTS. 



n. The diflference of heat between 

 the two troughs is so great, that it 

 is said, hothouse plants may be 

 struck in the trough It, and green- 

 house ones in g. The frame is 

 covered with the hand-glass 2^1 

 which of course may be removed at 

 pleasure. A new mode of heating 

 without either pipes or flues has 

 lately been discovered, but it has 

 only been applied to hothouses. See 

 PoLMAiSE Heating. 



Greenhouse Plants are those 

 Avhich will not bear the cold of a 

 British winter in the open air, but 

 that only reqiiire to be protected from 

 frost. Many persons injure their 

 greenhouse plants by giving them too 

 much heat in winter, and too little 

 air in summer, and are then surprised 

 to find their plants die, or at least 

 become sickly, and remain without 

 flowering, notwithstanding all the 

 care that has been bestowed upon 

 them. No greenhouse ought to be 

 kept at a greater heat at night than 

 from 35° to 40° dming winter ; but 

 the thermometer ought never to be 

 suffered to fall below 35°. In the 

 day, particularly if there be sunshine, 

 it will of course rise higher ; but the 

 fire should be lessened accordingly, 

 as the thermometer, even in sunshine, 

 should not rise in winter above 50°, 

 or at most 52° or 53°. A higher 

 temperatui-e will induce premature 

 vegetation ; and the plant will waste 

 its strength in an abortive attempt 

 to produce flowers and seeds at a 

 season when its nature requires it to 

 be kept in a state of complete repose. 

 The second fault, of giving too little 

 air, is an equally serious one. Plants 

 can no more live without fresh aii* 

 than without water ; and even in 

 winter, the sashes of a greenhouse 

 should be opened for an hour or two, 

 say from twelve till two, in the 

 middle of the day, whenever the sun 

 shines, or the frost is not too intense. 



In the summer, say from the middle 

 of May to the middle of September, 

 the plants should be set out in the 

 open air, the space on which they 

 are to stand being covered tv/o or 

 three inches deep with small coal or 

 slack, or ashes, to prevent the worms 

 from creeping out of the ground into 

 the holes at the bottom of the pots. 

 In cold and damp seasons, the time 

 for Tiutting out the plants may be 

 delayed till June ; and previously 

 to their removal, the sashes of the 

 greenhouse should be left open for 

 a week or ten days, night and day. 

 Grreenhouse plants should be watered 

 regularly every evening in summer, 

 and twice a day, if the v.-eather be 

 very hot and dry. In winter, they 

 should always be watered in the morn- 

 ing, when water is given ; but this 

 need not be every day. Some plants, 

 indeed, do not require watering 

 oftenerthanonceaweek. Thegeneral 

 rule is, frequently to examine the pots, 

 and to give water whenever the earth 

 appears to have become dry on the 

 surface. Greenhouse plants should 

 never be suffered to stand in saucers 

 during winter, as stagnant water is 

 peculiarly injurious at that season ; 

 and whenever the earth in a pot looks 

 black and sodden with w^ater, the 

 plant should be turned out of the 

 pot, and after the black earth has 

 been shaken from its roots, it should 

 be repotted in fresh soil, well drained 

 with broken crocks or cinders. In 

 February or March, the plants should 

 be looked over and repotted where 

 necessary ; those that are too tall 

 should be cut in, and cuttings made 

 of their shoots. The young plants 

 raised from cuttings made in autumn 

 should be repotted in larger pots for 

 flowering ; and where the plants do 

 not require fresh potting, but have 

 the surface of their mould become 

 green and mossy, the moss should 

 be taken off, and the ground slightly 



