Detailed Explanation of Sapling Grafting Methods and Techniques
SummaryBud grafting: a grafting method using a single bud with cambium, carried out from July to September. Cleft grafting: the scion can be a 2-year-old branch with 3-4 nodes, both sides need to be cut into equal wedges, inserted into the cut in the rootstock, then tied firmly. Approach grafting: leave two approach-graft cuts of appropriate depth on the scion parent branch and the rootstock parent branch, then bind and tie them firmly. Side grafting: a method of grafting onto the side of the rootstock. Cut grafting: a relatively commonly used grafting method.
I. Bud Grafting
1. Bud grafting is essentially using a single bud with cambium as the scion for grafting.
2. This method is generally carried out from July to September, and can use the “T”-shaped shield bud insertion method, which means cutting the scion bud into a shield shape, but the rootstock needs to be cut into a “T” shape to insert the scion into.
3. When preparing the rootstock, choose a smooth surface at the grafting site, preferably the north side, make a horizontal cut deep enough to reach the xylem, then make a vertical cut downward from the incision to form a “T” shape, then gently peel back the bark, insert the scion into the “T”-shaped cut, and finally wrap with plastic film from bottom to top, leaving the bud eye exposed, tie a slip knot, and it can be untied when the bud sprouts the following year.
4. After completing the graft, observe frequently; if the scion bud sprouts, be sure to remove the wrapping film promptly.
II. Cleft Grafting
1. Cleft grafting can also be called split grafting, and is often used on relatively thick osmanthus rootstocks or when top-grafting to change varieties.
2. When preparing the rootstock, note that the growing point and heart leaves need to be removed. When grafting, cut the rootstock off at an appropriate height, then use a cleft grafting knife to split vertically down the center of the rootstock cut surface, with the cut being 4-5cm, which is ideal.
3. Generally, the scion should be selected from 2-year-old branches with 3-4 nodes, with a length of 10cm, which is ideal.
4. Both sides of the scion need to be cut into equal wedges, then insert 2-4 scions into the cut in the rootstock so that the cambium layers of both are tightly joined together, then bind firmly with plastic film, and be sure to use film strips to cover the rootstock cut surface and the top of the scion.
III. Approach Grafting
1. The characteristic of approach grafting is that the rootstock and scion each have their own separate root system during the grafting process, and only after it is confirmed that the scion can survive on the rootstock are their root systems cut apart.
2. Generally, this method is carried out from May to June. When approach grafting, the branch used as the scion parent and the branch used as the rootstock parent can each have 5-10cm removed at an appropriate height, leaving roughly two approach-graft slant cuts with a depth of one-third to one-half of the stem diameter, align the bark layers so that their cambium layers are tightly joined, then bind and tie firmly with film, and after they survive, cut off the scion below the joined part.
IV. Side Grafting
1. This method is a method of grafting onto the side of the rootstock. When grafting, within 3-5cm from the root of the rootstock, use a knife to make a slant cut into the rootstock at 20-30 degrees, with a depth reaching one-third to one-half of the rootstock diameter.
2. The lower end of the scion branch can be cut on both sides into a 1-2cm double-sided wedge, and 1-2 pairs of buds can be retained. After the scion is cut off, insert it into the cut in the rootstock, align it with the cambium on one side of the rootstock, then bind the entire joined part well with plastic film strips.
V. Cut Grafting
1. This method is a relatively commonly used method for grafting nursery stock. When grafting, at 5-7cm from the ground, cut off the rootstock and trim it flat, and on the smoother side of the bark, cut vertically downward with a little wood included, with the cut being 2-3cm, which is ideal.
2. The lower end of the scion should be cut into a 2-3cm slant, then on the slant side make another short slant cut of about 1cm, and the scion needs to retain 1-2 pairs of buds; when cutting the branch, make a horizontal cut.