202 ADVANTAGES OF GROWING GREENHOUSE PLANTS IN FRAMES. 
Various objections might be brought forward against both the greenhouse and 
the open air, for the summer growth of the hardier kinds of plants requiring 
artificial culture. Only a few of those which refer to the former of these positions 
need here be urged. What we have already said respecting the insufficiency of 
solar light, must, with regard to some plants at least, be slightly modified. Heaths, 
for instance, appear to want occasional shading, when the sun's rays are very violent. 
But most other greenhouse plants would endure, and flower more freely under, a 
far greater degree of light, provided their roots were sufficiently excluded from the 
influence of the sun, and prevented from becoming too dry. It is their confine- 
ment in pots, the exposure of these latter to the solar beams, and the inability of 
the culturist to keep them duly moist under such circumstances, that causes the 
plants to look yellow and sickly ; and not, as is frequently presumed, the agency 
of light, except where this is poured upon them suddenly after they have been 
confined for some time in comparative darkness. To render as much protection as 
possible to the roots, plants of this nature should all stand on the same level, and 
their individual growth should be such as to secure the necessary umbrage to their 
own roots. Neither of these ends could be accomplished in the greenhouse ; for 
even a level stage placed near enough to the glass, would have an extremely 
unsightly effect, and materially check the circulation of air. 
From considerable experience, and attentive observation, we have found that 
the surest way of obtaining perfect specimens of greenhouse plants, is to place 
them, during their growing season, within a foot of the roof of any glass erection, 
to remove entirely, but temporarily, the lights or sashes of that structure, merely 
replacing them in cold weather, or when heavy rains are falling or expected to fall, 
and throwing a covering of thin canvass over the frame-work of the house when 
the sun is particularly fierce. This last operation would not be requisite to the 
plants in a natural state, but, from being long kept in pots, their acquired habits 
would, under the treatment above named, demand this or some similar precau- 
tionary measure in the early stages of their development. Such canvas would 
mitigate the sun s influence fully as much as the thickest glass, while its pervious- 
ness to air at once decides its greater suitability. Further, each plant should be 
elevated on an isolated pinnacle, at least two feet above the floor, stage, or other 
uniform surface. This is perhaps one of the most strikingly beneficial systems of 
management which the aspiring cultivator can follow. Assuming that the house 
in question has front and end moveable lights, when these are thrown open, it is not 
easy to conceive a more thorough circulation of air between, around, and through 
all parts of the plants, than would thus be ensured. 
Frames, besides being better adapted for carrying out this plan and supplying much 
greater facilities for its execution than greenhouses, are infinitely more economical, 
and can be kept in any private part of the garden ; or the mere fact of having to 
look down on the tops of the plants will effectually divert the eye of the spectator 
from the materials on which they are elevated. They would thus, even in the more 
