128 THE FORCING GARDEN. 



used for these with double the amount of hot- water 

 pipes, and a boiler capable of heating them, to be 

 double-glazed, with clips on my plan, according to fig. 

 7 or 9. The double glazing of this house is essential 

 for these plants, as they are, many of them, winter 

 flowerers, and it is the best for such a class of tender 

 plants, being safe, certain, and economical. If the 

 house containing this class of plants does, or must, face 

 the south, then select some appropriate climber for the 

 south roof, and I know of none better suited for this 

 purpose than an Allamanda, or a Jasminum, or a Bou- 

 gainvillea glabra ; each of these may be trained as you 

 please, covering the roof with a certain number of 

 permanent leaders and then spurred in as for a vine. 

 Thus the climber may be made to cover the roof thickly, 

 or to form a half-shade, which is the proper thing for 

 Gesneraceous plants : too much shade is not good for 

 them, but only so much as will break the full power of 

 the light. 



In attempting to grow this class of plants, it is 

 necessary to be careful and not to give the roots any 

 water when they are first excited, but to allow them to 

 make some little growth and then to give water suffi- 

 cient to half-wet the soil all through. The drainage 

 must be perfect, that is, one that will not admit of the 

 settlement of any water, but allow it to pass off directly; 

 thus the danger of too much water will be obviated. 



The tribe of Gloxinias are perhaps among our best 

 Gesneraceous plants. They may be raised from seed, but 

 as so few of them raised in this way are of much com- 

 mercial value, it is quite a speculation to do so. It is 

 much better to purchase a dozen or two well-known 

 sorts and to propagate them by cuttings of the leaves 



