How to Graft a Scion to a Rootstock: 5 Grafting Methods

In grafting, a scion is a plant cutting that connects with another plant, known as the rootstock. The process of grafting involves joining the tissues of two different plants to grow together. The idea is to take advantage of the rootstock plant’s root system and pre-established health while obtaining the desired traits of the scion plant. The scion, which is the top part of the new plant, will produce shoots and eventually bear leaves, flowers, and fruits, depending on the type of plant.

Grafting is an ancient method of plant propagation and modification. There are many advantages of grafting plants:

• Advantageous rootstock: One of the most common reasons for grafting is to take advantage of a well-established, hardy rootstock. This saves the gardener or horticulturist the risk of a new plant or tree failing to thrive and saves the time that a new plant—especially trees—would take to mature.
• Changing cultivars: The new growth of the scion and rootstock, if successfully grafted, will produce the new, desired cultivar or variety. In the case of fruit trees, an existing tree can produce a different variety of fruit once grafted. In addition to variety, grafting can have advantages of pest or disease resistance, productivity, flavor, and appearance.
• Perpetuating clones: A clone is a genetically identical specimen of a plant. Clonal horticulture can perpetuate specific traits of plants over long periods and in different locations. Often, horticulturists create clones via the processes of grafting and budding: one plant part is cut, grafted to a thriving rootstock, and allowed to grow.
• New characteristics: Dwarfing, which is the process of making varieties of plants small, has certain benefits. If a scion of a standard tree is grafted onto the dwarf rootstock, the new plant will take on characteristics of the old tree, which can lead to increased cold tolerance and higher productivity per amount of land. Apple trees are often grafted onto dwarf apple rootstock for this reason.
• Optimizing cross-pollination: Certain trees cannot self-pollinate and need nearby trees of a different variety to successfully flower and fruit. This can be impractical in some orchards, so horticulturalists will utilize grafting, adding a male plant scion to an existing female tree, thus permitting pollination.

There are different ways of grafting using scions and rootstock. Some of the most common grafting and budding techniques and their advantages are as follows:

1. 1. Budding: Instead of using a branch or twig as a scion, use a bud. The delicacy and small size of the bud make this process somewhat more challenging than others.
2. 2. Cleft grafting: This grafting method involves making a narrow, clean-cut known as a cleft in the base of the rootstock plant or tree. Insert a wedge of the scion wood into the cleft and bind with tape, grafting paint, or grafting wax. Over time, the tissues of the plants will grow together and form a successful graft union.
3. 3. Bridge grafting: This type of grafting is suitable for repairing woody perennials damaged at or near their base. Remove the damaged plant tissue, then cut small flaps into the bark above and below the damaged area. The grafting scions must be long enough to bridge the damaged area and should fit into the flaps of bark. Gently pull the bark back to insert the ends of the scions and secure the grafts with grafting paint or wax.
4. 4. Splice grafting: This grafting technique involves making a matched cut (two complementary angles, one on the scion, one on the rootstock) of two plants of the same diameter stems. Splice grafting works best for small, herbaceous plants.
5. 5. Whip and tongue grafting: This grafting process involves cuts with shallow angles in the rootstock and scion. Make an additional cut to produce a “tongue” on the surface of each cut. Ideally, these will lock together, helping form a tight seam and increasing the chances of a successful graft union. You can also bind with tape and grafting wax.

Grafting is a technically challenging procedure. Usually, advanced nursery operators and horticulturalists will attempt this method of plant propagation. Knowing what helps or hinders the processes of plant growth is essential to successful grafting:

1. 1. Use compatible plants. The closer the scion and rootstock plants are genetically, the more likely they will form a successful graft. Intra-species grafting of different varietals and cloned specimens are usually the most successful. Plants of varying species but the same genus can occur, and there are rare occasions when a successful graft union happens across families.
2. 2. Align the cambium. The more tightly pressed and closely aligned the vascular cambium layers of the scion and rootstock are, the more they are likely to form a graft union. (Cambium is a tissue layer that produces xylem and phloem cells, which are responsible for the secondary growth of plants.)The close alignment of the cambium allows for a better transfer of water and nutrients. Having sharp tools helps achieve clean-cut surfaces in both plants and is especially important with woody plants, which can be challenging to cut.
3. 3. Take care of graft site. Tools such as tape, twine, grafting paint and wax, all help ensure a close graft that retains moisture and nutrients. If the rootstock starts sending up shoots, this can interfere with the graft union forming, and so careful pruning is sometimes necessary.
4. 4. Properly store the scion. If there are multiple grafts to make, as in an orchard, it might take considerable time to prepare. If you do not plan to graft right away, you must store the scions. After you make the scion cuts, immediately wrap them in moist paper towels, place them in a plastic bag, and store them in a refrigerator or cold storage to keep them viable.
5. 5. Time the grafting appropriately. The conditions must be just right to perform a successful graft, which involves knowing the species and paying careful attention to weather conditions. Typically, the scion is grafted when it is dormant, in late winter or early spring, so excess moisture and energy are not lost to budding or growth. Both the scion and rootstock must be at a place where they can produce wound-response tissues, such as callus.

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