Technical method for grafting Golden Privet onto Glossy Privet

Golden privet (Ligustrum × vicaryi) is generally grown as a ball shape at ground level. To improve its ornamental value, the golden privet ball can be raised higher through grafting. Through experimentation, the author succeeded using glossy privet (Ligustrum lucidum) as the rootstock.

Grafting time: carry out the grafting in autumn when the weather turns slightly cool, before the plant's second growing season arrives.

Material selection and grafting: select robust, pest- and disease-free tall-stemmed glossy privet plants, and choose 4 to 5 branches per plant as rootstocks. On thick, pest- and disease-free golden privet branches, select well-developed, plump buds as scion buds. Use the shield budding method, bud grafting with a piece of wood. After grafting, wrap the entire wound layer by layer with plastic film to prevent infection. Generally, graft 8 to 10 bud points per glossy privet plant.

Management: after grafting is completed, carry out normal management, and the wound will begin to heal in about one month. In early April of the following year, after watering with spring water, remove the plastic film wrap and cut off the glossy privet branch 2 cm above the grafted bud. A few days later, the surviving golden privet buds begin to sprout. When the branches grow to about 10 cm, pinch off 2 to 3 cm from the tips of the branches.

Glossy privet and golden privet both belong to the family Oleaceae and the genus Ligustrum. The former is an excellent sub-tree for landscaping, but because it is so common, it is often overlooked. The latter is a colored foliage tree species and has been widely used in recent years. Because golden privet is a shrub, this limits its practical use. To expand the landscaping functions of both, the author used the method of top grafting to make up for each other's shortcomings and achieve this goal. The steps are as follows:

In spring, branch grafting or bud grafting can be used (the sap is already flowing, and it is best before budding). Use glossy privet with a diameter at breast height of 3 cm to 4 cm as the rootstock, and golden 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 2 cm-long incision; it is best if the incision just reaches the xylem. The scion can be 3 cm to 5 cm long, cut with a knife into a wedge shape of about 2 cm. The incision on the rootstock should be slightly longer than the incision on the scion. Next, quickly and accurately align the cambium layers of both. If the rootstock incision is too wide, two scions can be placed side by side. Then, use plastic strips of moderate thickness and elasticity to wrap upward from the lower part of the rootstock incision. When wrapping the joint where the two meet, you can apply a bit more force; when wrapping up to the upper part of the scion where there is no incision, wrap it evenly onto the rootstock. At this point, be sure to wrap the scion tightly and securely, otherwise the scion may dry out from wind or fail to heal completely. After grafting is finished, 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 2 cm-long incision at an appropriate position on the rootstock. When cutting the scion, be sure to include some xylem (not too thick), then align the cambium layers of both, and wrap upward from the bottom 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 one week, you can tell whether it has survived. If it failed, you can start over. If the grafting succeeded, you can remove the plastic strips, then gently wrap them back on. For branch grafting, the upper part may be left unwrapped; 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 may cause the rootstock to "stifle its buds" or even die. At this time, you can leave a bit more than 1/3 of the rootstock's branches and leaves to help the canopy and root system maintain physiological balance. When the scion buds grow 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 kept, and their growth can be controlled by pinching to lay 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 incisions 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. Branches sprouting from the middle and lower parts of the rootstock can be used for artificial shaping, either flat or spherical.