Page:On the cultivation of the plants belonging to the natural order of Proteeae.djvu/32

 8 earth at all times free from Mosses, which are the most pernicious of all weeds to many of these plants, especially when they attach to the base of their stems.

Air is indispensably necessary for them at all ages: after they are housed in autumn, if the weather continue temperate, admit it both day and night, by keeping off the glasses entirely, or in large houses all the windows and doors open. When there is any appearance of frost however, shut up the frames and houses, early or late in the afternoon, according to the degree of cold, opening them the following morning, as soon as the temperature rises to 36 degrees of Fahrenheiy's thermometer. In the depth of winter, when the frost is intense, cover the frames with mat, as well as the houses where it can be done conveniently; and by the help of fireheat, keep the temperature within, as near as may be to 34 degrees of Fahrenheit, during the night. It should never be higher than this in frosty weather during the night, for though it is not adviseable to let the temperature sink lower, very few of these plants will be injured, by occasionally experiencing 32 degrees of cold at that season: as these plants in general in their native state are subject to great violence of winds, particularly those that are inhabitants of mountains, which may in general be known by their robust and tree like habit, they should all be placed, so that the wind can circulate freely, not only amongst the branches, but also round the stems and pots, which in my opinion is of the utmost consequence to preserve health in the plants; and by close attention, I have often fancied an improved appearance between morning and evening, after a full exposure to a brisk wind during the daytime.

In one of the largest and most healthy collections of Cape and New Holland plants in this country, exposed on a bleak hill, the temperature of the principal house, during the months of December, January, and February, was always suffered to sink to 32