High-grafting method for large-leaf privet and golden-leaf privet

Large-leaf privet and golden-leaf privet both belong to the Oleaceae family and the Ligustrum genus. The former is a fine sub-tree for landscaping, but because it is so common, it is often overlooked. The latter is a colored-leaf tree species that has been widely used in recent years. Because golden-leaf privet is a shrub, this limits its practicality. In order to expand the landscaping functions of both, the author used the method of high grafting to draw on each other's strengths to achieve this goal. The steps are as follows:

In spring, use branch grafting or bud grafting (after the sap has begun to flow, and preferably before bud break). Use large-leaf privet with a diameter at breast height of 3 cm to 4 cm as the rootstock, and golden-leaf privet as the scion. First, choose the height of the rootstock and the angle of the branches. On the inner side of the base of a rootstock branch, use a sharp knife to cut a slit about 2 cm long; it is best if the cut just reaches the xylem. The scion can be 3 cm to 5 cm long, cut with a knife into a regular wedge shape of about 2 cm. The slit on the rootstock should be slightly longer than the cut on the scion. Next, quickly and accurately align the cambium layers of both; if the rootstock slit is too wide, two scions can be placed side by side. Then, use plastic strips of moderate thickness and flexibility to wrap upward from the lower part of the rootstock slit. When wrapping the union of the two, you can use a bit more force; when wrapping up to the upper part of the scion where there is no cut, wrap it onto the rootstock with even pressure. At this point, be sure to wrap the scion tightly and securely, otherwise the scion is prone to drying out in the wind or healing incompletely. After grafting is complete, appropriately thin out some branches and leaves of the rootstock; this work can also be done before grafting.

For spring bud grafting, use a knife to cut a slit about 2 cm long at a suitable position on the rootstock. When cutting the scion, bring along a certain amount of wood (not too thick), then align the cambium layers of both, and wrap upward from the lower part with plastic strips. When wrapping over the bud point, use a little less force to avoid damaging the bud. Whether the bud point is exposed depends on the weather.

After about a week, you can tell whether it has survived. If it fails, you can start over. If the grafting succeeds, you can remove the plastic strips, then gently wrap them back on. For branch grafting, the upper part need not be wrapped; for bud grafting, the bud point can be exposed to facilitate sprouting. Before the scion has sprouted, do not cut off all the branches and leaves of the rootstock, otherwise it will cause the rootstock to "smother its buds" or even die. At this time, leave a little more than 1/3 of the rootstock's branches and leaves to help the crown and root system maintain physiological balance. When the scion's buds have grown to 1 cm to 2 cm, you can cut off all the branches of the rootstock and remove the plastic strips. In subsequent management, the main task is to remove sprouts on the rootstock. Some sprouts on the rootstock trunk can be retained, and their growth controlled by pinching off the tips, which also lays the foundation for future shaping. Sprouts at the roots and around the scion should be removed to avoid competing for nutrients and disrupting the tree shape.

The two have strong compatibility, the cuts heal well, and the grafted seedlings grow vigorously. If water and fertilizer are supplied and management is proper, the crown diameter can reach about 2 m in two years, with golden branches naturally drooping. The sprouts growing from the middle and lower parts of the rootstock can be used for artificial shaping, either flat or spherical.