How are flowers grafted and propagated? A detailed explanation of the techniques and methods

Grafting is a propagation method in which a part of a flower's organ (a branch or bud, called the scion) is grafted onto another flower (the rootstock), so that they heal together into a new plant. The scion is generally selected from a superior variety, while the rootstock is generally a wild species or a seedling. The rootstock has a well-developed root system and grows vigorously; once the scion of the superior variety is grafted onto it, the plant can grow luxuriantly. There are 4 grafting methods: branch grafting, flat grafting, bud grafting, and approach grafting.

Branch grafting: Branch grafting is generally carried out in spring and is divided into cut grafting and cleft grafting. Cut grafting is suitable for rootstocks with stems 1~2 cm thick. The method is: select a fully grown branch, cut it into small sections about 6 cm long, keep 3 buds on each section as the scion, and wrap them in a damp cloth. When grafting, cut one side of the lower end of the scion into a long slant about 2 cm, and cut the other side into a short slant. Cut the rootstock off at a height of 5 cm from the ground, and make a straight, smooth cut of the same length as the cut on the scion. Then insert the scion straight into the cut in the rootstock so that the two fit closely together, tie them tightly with a strip, and then mound soil around them to cover them completely, leaving only the bud at the top exposed, so as to reduce water evaporation at the joint. Cleft grafting is suitable for thicker rootstocks. The method is: cut off the upper part of the rootstock, cut an identical slant (wedge-shaped) on each side of the lower end of the scion, then insert it into the cut in the rootstock, tie and secure the joined part tightly, mound soil around it and cover it completely, leaving only the bud at the top exposed to ensure that water does not escape, which helps survival.

Flat grafting: In flat grafting, both the base of the scion and the top of the rootstock are cut into smooth flat surfaces, pressed firmly against each other, and fixed by tying with thread. The cuts on the rootstock and scion should preferably be about the same size, and the center points must match and align. This method is often used for propagating cactus flowers.

Bud grafting: Bud grafting mostly uses the T-shaped method. First select a plump lateral bud on a one-year-old branch, remove the leaves, and make a horizontal cut above the lateral bud, then cut downward from bottom to top with a little wood attached, so that the bud piece is shield-shaped. Next, make a T-shaped cut on the shady side of the rootstock 5~6 cm from the ground, use the tip of the knife to lift open the lower end of the cut, insert the bud piece so that the upper end of the bud piece aligns with the bark of the horizontal cut of the T-shaped incision, expose the petiole and bud, and then tie it tightly with a strip. This method is generally carried out in late summer and early autumn.

Approach grafting: Approach grafting is often used for flowers that are relatively difficult to propagate, such as Michelia alba (white magnolia). Because the scion in approach grafting is not cut away from the mother plant and still receives water and nutrients from the mother plant, it is relatively easy to survive. When approach grafting, first pot the rootstock and press it close to one side of the mother plant, then cut a cut surface about 4 cm long on both a side branch of the mother plant and the rootstock, reaching deep into the xylem, so that the cambium layers of the two press against each other, then tie them tightly with plastic film strips. After the cut surfaces heal, cut off the scion below the joined part, and at the same time cut off the upper part of the rootstock, thus forming a new plant.