Grafting wax is a specialty wax that is used for sealing the cut edges of grafted plants. The wax seals the cut and prevents the graft cuts from drying out. Grafting wax is available commercially or can be made using a combination of beeswax and other ingredients.
There are several reasons why plants are grafted. A plant that has desirable growing characteristics but has a root system that is vulnerable to disease may be grafted on a more hardy rootstock. The seeds of many hybrid plants do not reproduce true to the parent plant and so are propagated using grafts. Some plants cannot be propagated using standard cutting or cloning techniques and must be started using grafting techniques. Regardless of why a plant is grafted, the application of grafting wax can mean the difference between a successful graft and a failure.
The process of plant grafting involves combining the upper part of a plant to the lower part of a different plant. The upper part of the plant, or scion, is cut away from its parent plant. The cut area is attached to a cut in the lower part, or rootstock, of another plant. In most cases, the scion and rootstock must be closely related plants for the graft to work. There are different methods of grafting, including whip grafting, cleft grafting, and bark grafting.
The last step in a graft is sealing the exposed areas. The cut sections of the scion and the rootstock are delicate and prone to drying out. The wax forms a protective barrier that prevents the graft from drying out. Once the graft takes and the plant begins to grow, the soft grafting wax will stretch with the new growth.
To apply the wax, it is held in the hands until it is soft and pliable. Alternatively, it can be warmed over a heat source until it has a workable consistency. Strips or strings of the wax are then applied to the cut area of the graft and flattened with the fingers until a watertight bond is created between the plant and the wax. When using a heat source, care must be taken to avoid overheating the wax as hot wax could kill the delicate tissues of the graft area.
Grafting wax can be found at garden supply and home improvement stores. It can also be made with a combination of resin, beeswax, and tallow. Some homemade grafting waxes contain resin, beeswax, linseed oil, and powdered charcoal.