Skill needed for grafting depends on technique

Last week, I wrote about the various ways grafting has been used to create street trees and repair injuries on girdled trees, as well as creating unique forms of plants. If it were not for grafting, we would not have nearly the variety of fruit of all sorts that we enjoy today!

As I wrote last week, the technique of grafting involves lining up the vascular tissues, the strawlike cells, of the stock and the scion, i.e. the xylem and phloem. With the help of some living cells nearby these vessels, fusion can occur and the straws become connected.

There are several different techniques for grafting that require various levels of skill and also luck. Most fruit trees and street trees are budgrafted. This process uses a single bud that is cut off the desired tree and inserted into a small cut in the stem of the stock tree. I had a friend at Cornell who worked in an apple tree production facility and he routinely achieved 90% or higher success with his single bud grafts. My results with bud grafting were somewhere around 10%, or even less.

Most of the time, bud grafting is performed in August as the tree is going dormant, but you can certainly try it right now as well. In early spring the bark of most woody plants “slips” or is easily peeled from the stock. Use a sharp knife both to cut the buds off the scion and to make a tiny “T” shaped incision in the stem or trunk you are grafting onto (stock).

For bud grafting, the T cut needs to be no more than a half inch in length and the stem tissue beneath the bud that you cut off, no more than quarterinch thick. Use the sharp point of your knife to tease away the bark and insert the bud so that it fits snugly into the slit.

Rubber bands are sometimes used to hold the bud in place tightly, but most of the time it is not necessary if the bud is covered with grafting wax. The grafting wax is to retain moisture and prevent the bud from drying out until it starts to grow. With luck, in another month or so the bud will begin to grow into a new shoot. When the new shoot is several inches long you can remove everything above it and the new shoot will become the dominant shoot.

I have had much better luck with what is called a “cleft” graft. This involves inserting a number of scions into the stock in the hope that at least one of them will take! It is also a good way to graft smaller scions into a larger branch or trunk.

Prepare the scions by cutting several shoots from your desired tree that are about the diameter of a pencil. Vigorously growing vertical branches, called watersprouts, are common on most fruit trees and are often just the right size for this.

These cuttings may be made and grafted right now, but I have had better luck doing the actual grafting in late April

or early May, even if the plant has begun to leaf out. If you make the cuttings now, they can be bundled into groups of 10, placed in a sealed plastic bag and stored in the refrigerator. Cut these into four- of five-inch lengths with at least a few buds remaining on each of them when you are ready to graft.

Using your sharp knife, carve about an inch of the bottom side of the cutting into a V shape, as

if you were sharpening a broken pencil tip, but only sharpen two sides to make a flat-shaped point and not a pencil point.

Next, prepare the stock by completely cutting off a branch that is about as thick as your wrist, leaving a stub that is at least a few inches long. You can also graft onto the main stem of a tree, if it is the same wrist-sized diameter.

With the tip of your knife, gently separate the bark from the inner wood of the stock just enough to insert the cutting into the separation. In late April or early May, the bark should

easily peel away and separate from the inner wood. You can usually insert three or four scions into a wrist-sized branch stub, thus increasing your odds of success.

Next, apply grafting wax on the whole operation to prevent desiccation. In a few weeks, at least one or more of the scions should begin to grow into a new branch and the others can be removed.