SOILS AND POTTING. 193 



well covered with Bussian mats and straw mats during 

 severe weather, and should the frost continue for several 

 weeks, they must not be uncovered until it is gone ; even 

 then the uncovering must be done gradually, and air must 

 be admitted very sparingly at first. Pits, however, that 

 are heated will not require to be so closely covered, and 

 the plants can therefore enjoy more light in vfinter, be- 

 cause there is then no danger that the inmates will be 

 frozen. 



Span-roofed pits or frames are also very useful, and can be 

 made to accommodate a choice and very interesting collection 

 of plants. In this case the middle wall is dispensed with, 

 the ends only are built up to the required height, and then a 

 stout beam is carried from end to end, to which the lights 

 must be fastened with hinges. 



In the summer, shading must be attended to as well as in 

 the greenhouse or stove. The tiffany, or any other material 

 used for the purpose, should be attached to rollers the width 

 of the lights ; this may be extended, if it should be desirable, 

 over the plants when the lights are off, and thus they will 

 receive a more abundant supply of fresh air. 



SOILS AND POTTING. 



HE soils best adapted for the growth of each genus, 

 are mentioned under their respective heads, and 

 need not be repeated here. The different kinds of 

 soils, and the method of collecting and stacking them, have 

 been explained in the division of this work devoted to Stove 

 Plants. The remarks there offered will apply with equal 



