Vlll INTEODUCTION. 



average day temperature of about forty-five degrees, and 

 thirty-six or eight at night. In very cold weather, however, 

 it is better to let the temperature stand at thirty-eight or 

 forty by day than to have recourse to much fire heat. 

 Under the same circumstances it is enough if the night 

 temperature is kept fairly above freezing point. The less fire 

 heat employed the better. If required, the growth of any 

 plants may be pushed on a little in February or March by 

 giving gentle fires in the early part of the day. In all the 

 mild weather of winter admit air freely by opening the 

 sashes, but not so as to cause a draught. In frosty, windy, 

 or foggy weather always avoid opening the greenhouse. x\s 

 spring advances give more and more air; but when the 

 growth is tender, especially avoid opening to cutting winds, 

 or so as to cause draughts : in such cases keep the windward 

 side closed, and open the other as wide as possible. A green- 

 house should never be shut up close when the sun is shining, 

 or when the external temperature is as high as forty degrees, 

 nor opened when it is frosty; and, so that this is observed, 

 tlie time of opening and shutting matters little. It is usual, 

 however, in winter to open as much as may be thought judi- 

 cious between 10 a.m. and 2 p.m.; and in spring the house 

 is opened about 6, or 8, or 10 a.m., and closed about -4 or 6 

 r.M., according to the state of the weather. In winter water 

 as seldom as possible, so that the soil never gets quite dry : 

 the same rule applies in summer, only then, instead of 

 seldom, the operation becomes much more frequent. 



GENERAL MANAGEMENT OF FRAME PLANTS. 



In the case of frame or half-hardy plants, or plants requir- 

 ing less warmth than a greenhouse affords, the preparation of 

 the frame is a most important matter. The bottom should 

 be firm and impervious to water, so that it may be kept as 

 dry as possible ; for which end it should slope in any one 

 direction, so that water spilt in watering the plants may run 

 into a gutter to be carried away outside the frame. The pots 

 should stand upon a trellis a few inches from the floor, and 

 this trellis is best made of narrow slij)s of wood placed a little 

 space apart. The sashes should be removed from such plants 



