Texas Agricultural Extension Service
The distinguishing feature of approach grafting is that two independently growing, self-sustaining plants are grafted together. This self-sustaining characteristic of both plants which are to be grafted insures survival of both even if the grafting attempt is, for some reason, not successful. However odds of being successful are greatly enhanced because of the active growing condition of both plants involved and absence of a time limitation required for the healing of the graft union to occur before the dependent scion (top portion) dies from lack of sustenance.
The approach grafting procedure is as follows:
- Plant an adapted, growing plant as close to the base of the non-adapted variety as possible without extensively damaging the root structure of the established plant.
- From both plants closely position shoots which are at least three-eighths inch diameter and preferably close to the same size. At the point where the union is to occur, a slice of bark one to two inches long is peeled from both stems. The peeled area should be the same size on each.
- The two peeled surfaces are then bound tightly together with budding or electrical tape. Wrap completely with two complete covers around the area where the two peeled areas are in contact.
- Remove some of the top portion of the foliage from the adapted variety six to eight inches above the graft union. This will encourage a more rapid healing of the grafted union.
- The union should be complete in four weeks. This type of grafting is most successful if performed during growth season.
- After the parts are well united (4 weeks or more),the remainder of the top of the adapted, native variety can be cut off immediately above the graft union and the bottom or root system of the non-adapted, yellowing plant can be cut off immediately below the graft union.
- The graft union is now completed and the problems of iron chlorosis and indigenous soil pathogens have been solved if the proper rootstock has been used. Immediately after the portion of each plant is removed it may be necessary to reduce the leaf area of the top if wilting occurs because of lack of sufficient root system support. This situation will soon stabilize. If the only problem has been micronutrient (iron chlorosis) deficiency, the top, unadapted variety will not need to be detached from its own root system–the approach grafted, adapted variety root system will “feed” the sickly plant what it needs. However, if the purpose of the graft is to control soil borne diseases, the susceptible variety should be detached from its root system and become totally dependent on the root system of the adapted variety.