Grafting

Tape has been used to bind the rootstock and scion at the graft, and tar to protect the scion from desiccation.
Graft particular to plum cherry. The scion is the largest in the plant, due to the imperfect union of the two. It can be seen on the enlarged trunk: this accumulation of starch is an indication of imperfection.

Slide the wedge into the cleft so that it is at the edge of the stock and the centre of the wedge faces are against the cambium layer between the bark and the wood. It is preferable if a second scion is inserted in a similar way into the other side of the cleft. This helps to seal off the cleft. Tape around the top of the stock to hold the scion in place and cover with grafting wax or sealing compound. This stops the cambium layers from drying out and also prevents the ingress of water into the cleft.

The stock is cut through on one side only at a shallow angle with a sharp knife. (If the stock is a branch and not the main trunk of the rootstock then the cut surface should face outward from the centre of the tree.) The scion is similarly sliced through at an equal angle starting just below a bud, so that the bud is at the top of the cut and on the other side than the cut face.

In the whip and tongue variation, a notch is cut downwards into the sliced face of the stock and a similar cut upwards into the face of the scion cut. These act as the tongues and it requires some skill to make the cuts so that the scion and the stock marry up neatly. The elongated "Z" shape adds strength, removing the need for a companion rod in the first season (see illustration).

The joint is then taped around and treated with tree-sealing compound or grafting wax. A whip graft without a tongue is less stable and may need added support.

Stub grafting is a technique that requires less stock than cleft grafting, and retains the shape of a tree. Also scions are generally of 6–8 buds in this process.

After the graft has taken, the branch is removed and treated a few centimeters above the graft, to be fully removed when the graft is strong.

The four-flap graft (also called banana graft) is commonly used for pecans, and first became popular with this species in Oklahoma in 1975. It is heralded for maximum cambium overlap, but is a complex graft. It requires similarly sized diameters for the rootstock and scion. The bark of the rootstock is sliced and peeled back in four flaps, and the hardwood is removed, looking somewhat like a peeled banana. It is a difficult graft to learn.

Awl grafting takes the least resources and the least time. It is best done by an experienced grafter, as it is possible to accidentally drive the tool too far into the stock, reducing the scion's chance of survival. Awl grafting can be done by using a screwdriver to make a slit in the bark, not penetrating the cambium layer completely. Then inset the wedged scion into the incision.

Rind grafting involves grafting a small scion onto the end of a thick stock. The thick stock is sawn off, and a ~4 cm long bark-deep cut is made parallel to the stock, from the sawn-off end down, and the bark is separated from the wood on one or both sides. The scion is shaped as a wedge, exposing cambium on both sides, and is pushed in under the back of the stock, with a flat side against the wood.

The transmission of plant viruses has been studied using grafting. Virus indexing involves grafting a symptomless plant that is suspected of carrying a virus onto an indicator plant that is very susceptible to the virus.

Grafting is also mentioned in the New Testament. In Romans 11, starting at verse 17, there is a discussion about the grafting of wild olive trees concerning the relationship between Jews and Gentiles.

A New Orchard and Garden: Or, the Best Way for Planting, Graffing, and to Make Any Ground Good for a Rich Orchard, Particularly in the North