CONSERVATIVE WALLS. 
183 
kept in a warmer temperature than just what is sufficient to preserve them from 
injury, they progressively become more and more susceptible of harm ; thus, if 
covered up too much from the ordinary atmosphere in the early part of winter, 
they will be far more liable to be destroyed towards spring by a low temperature, 
than they would have been had a contrary course been pursued. We are the 
more urgent in enforcing this point, because it is one of vital moment in the culture 
of tender exotics on a conservative wall. Many plants which had existed through 
the depths of winter, have been lost on the approach of spring, owing to that 
precocity of growth which too much protection fosters. 
Winter management, then, is merely to consist in guarding the plants from 
frost, and at the same time endeavouring, by frequent well-timed exposure to the 
air, to delay as long as possible the increasing tendency to renew growth. But 
the growing principle once re-excited, the capacity of the plant to endure cold is 
diminished— the new parts being exceedingly tender, require more warmth to 
enable them to go on extending with vigour. A frost which before would have 
left no traces of injurious action behind it, will now be fraught with danger. 
This is a rock on which many split, after having carried their charge through 
the most intense cold in perfect safety : as soon as mild weather appears, they at 
once set about removing the means of protection, forgetting the delicate organs 
that it encourages to form, and the spring frosts, which are still to be apprehended 
and guarded against ; hence the shoots are destroyed, or starved into an imbecile 
diseased growth, and much time is lost before the plant recovers a healthy 
condition. It is no wonder that many plants fail to thrive and flower well under 
such treatment ; for the shoots cannot reach maturity before they are overtaken 
by another winter. 
At Chatsworth the plants on the conservative wall are protected in winter 
with canvass curtains suspended from an iron rod placed beneath a moveable 
wooden coping, and fastened at the bottom at short distances by means of rings 
and hooks. The hooks are fixed to a board about ten inches broad, which runs 
along the bottom, and is attached by hinges to a frame-work firmly set in the 
ground : when the curtains are drawn back, the board lays partly over the border, 
with the hooks towards the earth, and makes a convenient path to stand upon 
whilst dressing the trees. The curtains are opened and closed by cords moving on 
pulleys ; in the day-time they are neatly drawn up and secured to the projecting 
buttresses. There are two to each compartment ; hence, to cover the wall these 
meet in the middle ; and as one curtain is provided with eyelet-holes, and the 
other with rings to pass through them, they are readily fastened together by 
running a cord through each of the rings from the top to the bottom of the wall. 
The whole, except the board into which the hooks are driven, can be entirely 
removed in summer. In severe weather a quantity of dried fern is thrown up 
against the bottom of the curtains, and the fined walls are warmed by gentle fires. 
It must be remembered, however, that this is in a cold elevated district, where 
