83. Dwarf trees were formerly much in vogue ; and, strange as it may appear, the prospect of fruit was gene rally sacrificed to a fine shape. It was thought necessary that the lower branches should spread horizontally near the ground, and should decrease in width upwards, so that the tree should have a conical form. Now, it is well known that the fruit-buds of pears and apples in general, and of many sorts of plums and cherries, are produced at the end of the former year's shoots, which therefore should remain at full length ; yet these were necessarily shortened, in order to preserve the desired shape, and it may easily be conceived that trees so dressed could not prove fruitful. For these reasons, the training to espalier rails has generally been preferred. A few dwarf trees, however, prove ornamental, and they sometimes afford a great deal of fruit. The kinds of dwarf fruit-trees now in request are chiefly pears and apples. The pears must be of the summer and autumn sorts, the later fruits re quiring a wall in our climate. Dwarf pears are chiefly budded on quince stocks. The trees are planted out, at two or three years old, where they arc to remain, and they are placed from 20 to 25 feet asunder. A few stakes are driven into the ground, and, by means of tying down, the lower branches may soon be made to acquire a horizontal direction. No branches must cross each other, and no central upright shoots are permitted. The only other par ticular to be attended to is, when the trees are to be train ed in a concave form, that, in shortening the shoots, the uppermost eye or bud is to be left outwards, as in this way the hollowness in the middle of the tree is better pre served. Sometimes the branches are trained round a hoop, which is supported by three or four small poles. Dwarf standard apple trees on paradise stocks may be planted very closely, as they occupy but little room : they do not require more than 10 or 15 feet ; on crab stocks they need at least 25. Plums are now seldom planted as dwarf-stand ards; cherries more frequently ; apricots scarcely ever.
Preserving of Blossom.
84. In this country, particularly on the east coast and in the northern division of the island, it is an important part of the gardener's duty, to preserve the blossoms of apri cots, nectarines, peaches, and the finer sorts of plums, from being destroyed by spring frosts, and especially frosty winds. One of the means first employed is still occasion ally resorted to ; namely, shading the trees slightly with branches of spruce fir, yew, or beech ; but the branches ought to be so firmly fixed as not easily to be displaced by the winds, or to shake much : if this precaution he neglected, they will be ready to beat off the blossom which they are intended to defend. Strong fronds of the com mon brake (Pteris aquilina) have been used with advan tage in this way ; being the remains of the former year's growth, they are light ate dry, and much less apt to in jure the blossom than branches of trees.
The most effectual protection, however, is afforded by canvas•screens, in moveable frames ; the fabric of the canvas being made thin enough to admit light, and yet af fording sufficient shelter. The stuff called buntinc, of which ships' flags.are sometimes formed, is recomm6nded by Nicol ; and he adds, that it may be rendered more trans parent, and more durable, by being oiled. The stuff called osnaburg, manufactured in the towns of Dundee, Arbroath, and Montrose, answers equally well, especially if made on purpose, of a wider texture, so as to resemble gauze.
These screens are kept clear of the tree, a foot at top, and 18 inches at bottom. lf, when not in use, they may be stowed in a dry loft, they last for many years. Sometimes the canvas is used in the form of sheets to hoist up and down; and in some places (as at Dalmeny Park garden, one of the finest in Britain) the contrivance is such, that the covering can be drawn up or let down the entire stretch of the wall, by two men, in the course of a mi nute. These screens are employed only at night, or in bad weather; and chiefly from the end of March to the beginning of May. Blossom thus partially- protected is perhaps more tender than if no protection whatever had been given. The screens must therefore be continued till all risk of danger be over ; perhaps till the leaves of the tree be pretty fully expanded, the blossom of seve ral of our fruit-trees preceding the unfolding of these.
Frames covered with oiled paper have been successfully employed at Grangemuir garden in Fifeshire. The frames are of wood, inch and half square, with cross bars mortised into the sides. To give support to the paper, strong pack thread is passed over the interstices of the frames, form ing meshes about nine inches square. Common printing paper is then pasted on; and when this is quite dry, a coat ing of boiled linseed oil is laid on both sides of the paper with a painter's brush. These frames are placed in front of the trees, and made moveable, by contrivances which must vary according to circumstances. If the slope from the wall be considerable, a fewtriangular side frames may be made to fit the spaces. At Grangemuir, the frames are Not put up till the blossoms be pretty well expanded ; till Which time they are not very apt to suffer from spring frosts or hail showers. In this way, it may be remarked, there is much less danger of rendering the blossom deli cate by the covering, than if it were applied at an earlier period. The paper frames, if carefully preserved when not in use, will endure for a good many years, with very slight repairs.
At Dalkeith garden, in order to break the force of the winds, screens made of reeds are projected, at right an gles with the wall, perhaps to the distance of ten feet, and at intervals of thirty or forty feet from each other ; and at the same tittle nets wrought With straw arc placed in front of the trees. These straw nets are very well deserving the attention of gardeners who may find their walls too much exposed to the cast winds during the spring months. Old fishing-nets, kept at the distance of fifteen or eighteen inches from the tree by means of hooked sticks, are some times employed ; these may be doubled over, in order to render the interstices closer. But nets made of coarse woollen yarn or carpet-worsted, arc preferable to these. At Iladdington, in East Lothian, woollen nets for this pur pose are manufactured in the loom, and can thus be afford ed at much less expellee. They are woven very thick, the meshes not being larger than to admit the point of the finger, even when stretched out. The advantage of wool len yarn over flax for this purpose is evident ; every small mesh being in effect rendered still smaller, by the bristli ness of the material, and its constant tendency to con tract ; and from its aptitude to attract and concentrate moisture, such as cold dews and hoar-frost, the blossom derives additional security. These nets, and indeed nets of any kind, remain on night and day, till the season be suffi ciently advanced.