Comparatively little has been done as yet in top-working the stone fruits. But Western experience with the cherry leads to the belief that it will pay commercially to top-work the cherry and plum on vigorous deep-rooting stocks. In Dupage County, Illinois, over forty years ago James Wakeman top-worked Early Eichmond on stocks now known as American Morello. The history of this variety is not known. It is worthless for fruit where better varieties can be grown, but it has remarkable vigor and hardiness and has been scattered by means of sprouts over the whole Northwest. The large commercial orchards top-worked on this stock have borne heavily and regularly and have outlived two or three generations of Early Eichmond nursery-grown trees on mahalob roots.
The same favorable experience has followed the use of this hardy stock in many parts of the West. At first the trees sprout but, when they come into heavy bearing the sprouting mainly ceases to give trouble. The wild red cherry (Prunus Pennsylvanicą) has also been used successfully as a stock. All varieties worked on it have proven hardier, lived longer, and have borne more regularly and profusely than the same varieties root-grafted or budded.
With the plum the benefits of top-working have been less apparent, except in the way of top-grafting select native varieties on native plum seedlings. Where the Japan and all foreign varieties have been top-grafted on native stocks they have come into bearing very young, but the top soon outgrows the stock and breaks off with the heavy load of fruit. This does not seem to arise from weakness of the stock, but from the hardening of the outer bark below the grafts. By slitting and peeling off the bands of outer cuticle the season after the grafting is done we have secured an even growth of scion and stock, both with the cherry and plum. Contrary to usual belief the top-working of cherry and plum is as easy and certain as grafting the apple or pear if the work is done very early with dormant scions and where the stocks are perfectly dormant. The side-cut method is employed on relatively small stocks, but on older stocks the cleft-and-wedge plan gives as good results.
If sprouts or seedlings of any of the orchard fruits are taken up late in autumn and stored in cellar with proper root-covering they can be top-grafted during winter indoors and set in orchard the next spring. In this system a single scion is inserted in the stock at proper height to form the top. After grafting the only care needed is root-protection and care in handling to prevent breaking off the scion. When set in orchard or nursery shoots will start below the scion. These are left until the scion has made some growth, when they are rubbed off. This method is useful to amateurs, but is rarely practised in nurseries except with some shrubs, and the grafting of the gooseberry on Ribes aureum stocks.