This operation may be performed regularly every two or three years, until the tree has arrived at full size and bearing, and even afterwards an occasional root-pruning will be found of much benefit. It will be unnecessary for us to go into more detail regarding the further pruning and training of the Plum, as in most particulars it is the same as recommended for the Pear. It is a good thing, however, to be always introducing a few fresh shoots, as the older branches and spurs sometimes become a little exhausted, and are all the better for being renewed. This is a good method to adopt, as sometimes the spurs become so attenuated and far removed from the wall that it is necessary, for appearance' sake, to have them removed - so that, where such provision is made, no blank will be made, and their want will not be so much felt.

Plums are very seldom used as riders, but where this is the case, they ought to be either grafted or budded about 6 feet high, or have a leader grown up to that height from the dwarf-worked trees, when they may be cut over at the same height, and managed in exactly the same manner thereafter, as we have recommended for the dwarf-trained trees. The principal use to which these trees may be put is between the dwarf-trained ones, to fill up the walls until such time as the permanent ones are large enough to nearly do so themselves. Looking at the matter from an economical point of view, we would not recommend them, as the plum being a rapid grower, the dwarf trees would require the greater part of the wall to themselves before any great crop could be expected from the riders, unless they were established and bearing trees when planted.

If the horizontal mode of training is to be adopted, let the leader be cut back as already directed to about 9 inches from the ground, leaving three nice plump buds at the top for the leader and the two first horizontal branches. At the end of the first year's growth, cut the leader back to within about 9 inches from where it started, leaving, as before, three nice buds to form a centre and the second course of branches. The side shoots may be cut back to the first bud as far out as the wood is ripe, as it will not be necessary to cut so far back in this mode of training as in the fan, as no side shoots are required except from the centre. The side branches ought to be elevated at an angle of about 45°, and be gradually lowered until they arrive at the horizontal line about 1 foot from the ground. The same course of pruning and training may be regularly pursued year after year, until the tree has reached the top of the wall, when it should have a regular course of branches from top to bottom, about 9 inches apart, which we consider to be wide enough for almost all sorts of Plums, except a few of those possessing very large leaves, which may be benefited by having the distances between the branches increased to about 1 foot apart.

It will be found of great advantage and benefit to the trees if the cultivator would go regularly over them in summer, during the growing season, and pinch back all the shoots save those intended for branches to the fourth or fifth leaf. These in turn will probably produce laterals, which may be pinched back to the first eye from which they started, and at the winter pruning the original shoot should be cut to about 1 inch in length. This will, in all probability, form a fruit-bearing spur; but should it not do so the following season, but send forth shoots again, these may be treated as before, until such time as it shall form a fruiting spur.

In the case of a tree still continuing to grow very unequally after the means already directed have been adopted, the following plan may be found of great benefit. We never have adopted it ourselves, as we never needed to do so, nor yet have we seen it performed by any other; yet we have every confidence in its efficacy, as it has been adopted with success by one whose word on everything connected with fruit-tree culture can be depended upon. Mr Thompson, in the 'Gardener's Assistant,' thus says regarding it: "In addition to other means tending to diminish excess of vigour, some of the leaves should be clipped across the middle with sharp scissors. Every third leaf may be safely clipped in this manner; if that is not likely to prove effectual, every alternate leaf may be so treated; and in obstinate cases we have seen every leaf on a shoot clipped half away with no injurious results, but, on the contrary, with the most beneficial effects, inasmuch as wood of only the requisite thickness was obtained, instead of a shoot too thick to be retained in that part of the tree, and which would consequently have to be cut away at the winter pruning.

Thus a considerable waste of vegetation is avoided, as well as the probability of inducing disease, for gumming frequently takes place when very strong shoots are cut off." This appears to be a very practical and at the same time simple and safe remedy, and is well worthy of a trial by those who may have failed to obtain an equal distribution of the sap all over their trees. However lightly some may look upon it, yet, nevertheless, it is a thing of the first importance, and should be carefully attended to, as, if the sap is not dispersing itself in pretty equal proportions all over the tree, it cannot and will not long continue to enjoy good health - nay, more, the very life and fruitfulness of the tree are at stake, and the sooner the matter is set to right, so much the better it will be for the future wellbeing of the tree.

Another thing of vast importance, always to be observed in the wall cultivation of the Plum, is never to allow shreds or string to become so tight upon the bark as to mark or injure it in the least. If this should occur to any extent, the probability is, that if the branch is not broken over altogether, gumming will be the after-result. The nails should also be kept some distance back from the branches, for if they come in contact with them, or should the hammer in driving them in strike or bruise the branch in the least, gumming or canker, or perhaps both, will be the consequence.

James M'Millan. (To be continued).