In mulching the object is to prevent evaporation from the soil, as well as to shield the roots from sudden changes of temperature; it is often necessary to protect the whole plant in this respect, and this is accomplished by shading. Although on a large scale, we can do little in the way of shading plants in the open ground, yet the amateur will often find it of great utility, as screening will frequently save a recently transplanted plant, which without it would be quite ruined by a few hours' exposure to the sun. For shading small plants inthe border, such as transplanted annuals, a few shingles will be found very useful, one or two of these can be stuck in the ground so as to completely protect the delicate plant and yet not deprive it of air. Six-inch boards of half-inch stuff nailed together to form a V shaped trough are very useful in the garden; they are handy to place over small plants during cold nights, and may be turned over and set to make a screen against strong winds, or used for shading plants in rows. Seedlings often suffer from the heat of the sun in the middle of the day; the seedlings of even the hardiest forest trees are very delicate when young. The seeds of such trees when sown naturally almost always fall where the young plant will be shaded, and the amateur who experiments in this very interesting branch of horticulture, the raising of evergreen and deciduous trees and shrubs from seed, will find it necessary to imitate nature and protect his young seedlings from the intense heat of the sun. There are several ways of doing this; if the seeds have been sown in an open border, let him take twigs about a foot long, evergreen if they can be had, but if not, those from any deciduous tree, and stick them a few inches apart all oyer the bed. This will give the seedlings very much such a protection as they would naturally have had in the shade of other plants, and though evergreens will look better for a while, the dead leaves of deciduous twigs will give quite as useful a shade. It is always safer to sow seeds in a frame, as the young plants are then under more complete control. Frames are easily shaded by means of a lattice made of common laths. Strips of inch stuff an inch and a half or two inches wide, are used for the sides of the lattice, and laths are nailed across as far apart as their own width. One lath being nailed on, another is laid down to mark the distance, the third one put down and nailed, and the second lath is moved along to mark the distance for the fourth, and so on. With a screen of this kind there is abundant light, but the sun does not shine long at a time on one spot, and the plants have a constantly changing sun and shade. This lath screen may be used for shading plants in the open ground if supported at a proper hight above them. In a propagating house, where it is necessary, as it often is, to shade cuttings, a lattice laid upon the outside of the glass answers a good purpose. The laths are sometimes tied together with strong twine, the cord answering the place of slats, and serving as a warp with which the laths are woven; the advantage of a screen of this kind is that it can bo rolled up. Plants kept in windows during the summer months will, if in a sunny exposure, require some kind of a shade, and if the one provided to keep the sun from the room shuts out too much light, or excludes air as well as sun, something must be provided which will give protection during the heat of the day, and still allow sufficient light and an abundant circulation of air. Any one with ingenuity can arrange a screen of white cotton cloth to answer the purpose.
The old practice of stripping the greenhouse in summer is falling into disuse, and by a proper selection of plants and sufficient shade, it is made as attractive then as at any other season, but even for tropical plants the glass must be shaded. For a small lean-to, a screen of light canvass or muslin arranged upon the outside, so that it may be wound up on a roller when not wanted will answer, and if it be desired to keep the house as cool as possible, this should be so contrived that there will be a space of six inches or so between that and the glass. But upon a large house, or one with a curvilinear roof, this is not so manageable, and the usual method is to coat the glass with some material which will obstruct a part of the light. The most common method is to give the outside of the glass a coat of ordinary lime whitewash; this makes a sufficient shade, and is gradually dissolved by the rains, so that by autumn the coating is removed, or so nearly so that what remains may be readily washed off. A more pleasant effect is produced by spattering the glass with the same wash, which can be done by a dexterous use of the brush and flirting it so as to leave the wash in numerous fine drops, like rain-drops. Others use whiting and milk for the same purpose. Whatever may be the means of effecting it, we find that in this latitude shading of some kind is required from about the 1st of May to the middle of September by nearly all plants grown under glass. Ferns, Lycopods, Caladiums, Primulas, Fuchsias, Begonias, Gloxinias, Achimenes, Lobelias, Smilax, and plants of that character require the glass to be heavily shaded, while for Roses, Carnations, Bouvardias, Poinsettias, Geraniums of all kinds, and nearly all succulent plants, do not need so much. The method of spattering the glass outside with thin whitewash, allows the shading to be light or heavy, as required. When first done, it is spattered very thinly, merely to break the strong glare of the sun, just about thick enough to half cover the surface. As the season advances, the spattering should be repeated to increase the shade, but at no time for the plants last mentioned do we entirely coyer the glass. In England, especially for fern houses, Brunswick green mixed with milk is used, to give a green shade, which is thought to be best suited to these plants. The blue glass for greenhouses which was so highly lauded a few years ago, has not met with much favor, but recent experiments in glazing with ground glass have given such results as to warrant a more careful investigation into the use of this material.