These species of trees are injuriously affected by exposure to dry cold winds, even when their roots are undisturbed by removal; but if planted at a season when several months must elapse before any perfect action can commence, the tops are apt to become dried up in the interval. It appears that if their juices become inspissated to a certain extent, they never again become liquified, probably owing to their resinous nature.
The watering of newly planted trees ought to be attended to. The supply in the first instance should be copious, in order to wash the earth into the cavities among the roots. Some err in keeping the roots of newly planted trees constantly soaked with water, as if they were those of bog-plants, for which only such treatment is proper. In watering, consideration should always be had to the nature of the plant, to which, if it delight in dry soils, no more water should bo artificially applied than is necessary to moisten it as much as the soil in which the species grows naturally, and at a time wheu shoots and leaves are abundantly produced. When watering is performed, it should be done thoroughly, so as to reach the lowest portions of the root. In the case of plants being much dried from long carriage or other causes, the supply on first planting should be very moderate. The tope however should be frequently syringed, in order to moisten the bark and prevent its absorbing the organisable matter which deacends towards the root by the inner bark. The flow must be extremely weak under such circumstances; but if it can be preserved from the effects of drought till it reach the extremities of the roots, the formation of fresh epongioles will immediately commence, and the tree may then be pronounced out of danger.
The manner of performing the operation of planting may be reduced to one general principle, that of placing the roots in the soil so as to imitate as closely as !possible the position which they occupy when growing will and uncontrolled. Plants indeed may be instanced whose roots have been observed in one situation penetrating to the depth of four or five feet ; or in another, creeping along the surface, amongst stones, or into the crevices of rocks, with scarcely soil to cover them, as for example in the vine. But although roots can usually accommodate themselves to that position which the nature of the situation renders it alone possible for them to occupy, yet there can be no doubt that in all oases the extremities of the roots should be lower than where they diverge from the stem, a rule which, however self-evident it may be, is frequently violated in practice by making a 1, basin-shaped hole, deepest In the middle, in which the roots are either doublet or have their extremities tending upwards on the sloping sides of the cavity.
The excavation for the reception of the roots of a plant should be considerably larger than those roots will traverse when extended at the time of planting. It should be as wide at bottom as at top. The bottom should be more or less convex, and the depth such as to admit of the roots being covered to the extent observed in undisturbed seedling plants of the same species; that is to say, the upper part of the rout should only bejust covered. The lower roots should be disposed over convex bottom of the excavation, andcarefully strewed with some of the finer portion of soil,over which the other roots may be spread. .11ore soil should then be carefully rather than forcibly introduced. There should be no vacant spaces left, except those of so minute a description that they will be readily filled up by the finer particles of earth washed down by a plentiful watering. This watering should be given when the soil is nearly all filled in ; and after the water has subsided so as not to stand above the surface, the latter should be covered with the remaining portion of soil. Except in very loose or light soils, this method will supersede the necessity of the hard beating and treading in to which the roots of trees are very generally subjected. The latter practice is now however being laid aside by many, from a conviction of its injurious effects. It is also necessary to remark that a plant should be placed, before the intro duction of the soil, exactly as it is intended It should stand; and it should not be pulled from side to side for the purpose of shaking the earth amongst the roots. If the tree be drawn to one side, the fibres of the root will also be drawn towards the same side; but they are of course too flexible to force their way back when the tree is drawn in a contrary direction, and they must therefore become more or less doubled. Nor should the soil he thrown against the fibres whilst the roots are being covered ; it should be made fine, and either shaken from the spade so as to fall perpendicularly among the roots, or scattered by a force impelling it in the direction of the fibres, which will be ht general from the stem towards the extremities, or from the centre to the circumference.