Grafting, including budding, may be defined as inserting a piece of wood which carries buds of a desired variety, on a root stock sufficiently compatible to accept it, for the purpose of propagation. Methods vary, each nurseryman having one or more which he prefers, but the principle is always the same.

Scionwood may be cut the fall before grafting is to be done, after the growing season has ended, but some prefer to cut the scions in early spring. This means that the scions must be stored until time to graft, and correct storage is so important that nurserymen make elaborate provision for it. I have found that keeping scions underground in a Harrington graft storage box is the safest method. An illustration of this box is given, with directions for its construction and location. A small quantity of scions may be kept in an icebox (not a mechanical refrigerator), by cutting them into convenient lengths of one or two feet, dipping them in melted beeswax, wrapping them in tar or asphalt paper and placing them close to the ice. They will remain in good condition for several months if there is always a good supply of ice. Care must be taken in dipping the scions in melted wax, for if the wax is too hot it will injure the buds. It should never become so hot that it smokes. I find it advisable to keep an unmelted piece of wax in the liquid wax to hold the temperature down.

Another method of storing scions, after they have been dipped in beeswax, is to place them on the earth of a cellar floor and cover them with a few burlap sacks. They should never be allowed to become wet or they will start to mold. If they are to be stored in this way, a watch must be kept for mice which will molest them and destroy them if they have an opportunity.

Although bud wood may be stored in any of the three ways mentioned, it should not be waxed. Because of this, it is more likely to deteriorate. It must be examined frequently and if mold is found, the wood should be dipped in a Bordeaux solution. After drying, it may be placed in storage again. It is a good plan to wrap bud wood in tar or asphalt paper when storing it. However, I have found that the best storage conditions for all scionwood that I have yet discovered is in the use of peat moss. Peat moss must be on the distinctly acid side in order to perform the function of storing scionwood. Most peat moss is generally acid; however the simple litmus paper test with which every high school pupil is familiar, can be made. Having acquired good acid peat moss, dampen a sufficient quantity to pack the scions in to give them liberal protection. Do not make the bundles of scionwood too large, from 10 to 20 scions in a bundle is better than a large number and much easier to handle. The moss should be prepared exactly the same as advised in storing chestnuts (see chapter for storing seeds). In this case it is not necessary to wax the scions at all. The moss should be applied by sifting it into the open spaces between the scions and a larger wad at the base of the cuttings, not at the terminal or bud ends as these would be better left unpacked. The package is now rolled into a cylinder, using tar paper or asphalt treated paper, and both ends left open. Do not use ordinary paper or wax paper as it will turn moldy. Cylinders of tar paper containing the packed scions should be placed in a damp room like a cellar with a dirt floor which is cold enough to keep potatoes and other roots in good condition throughout the winter. If the cellar is not a good storage cellar for roots and herbs it will not be good enough for the scionwood as it will be too warm generally. Neither should they be frozen solid, therefore if a good root cellar is not obtainable then these should be put in the Harrington graft box already described or placed under the sawdust in an icehouse and close to the ice. An old-fashioned ice refrigerator will also make a good storage bin, placing them close to the ice at all times.

Making a scarf with a plane preparatory to grafting.

Selection of good scionwood and bud wood, a very important matter, is made according to definite standards. Some plants graft better if wood is used that has two seasons' growth, but, in general, wood of the current season's growth is used. It must have reached its maximum possible maturity before it is cut. Also, some attention should be paid to the vigor of the growth which it has made during the season. For instance, in choosing between wood which has made only two or three inches' growth and that which has made a foot or more of growth, both being equally sound and mature, the more vigorous should be chosen. Attention should be paid to the development of the buds, which should be plump and never immature.

It is advisable to label scions before they are stored to avoid the confusion that will result if they are mixed. I find that the best method of doing this is to get a sheet of zinc, from 20 to 30 gauge thick, and cut it into strips one inch wide by one and three-quarters inches long. I bore a small hole in one corner of each tag, through which I thread 18-gauge copper wire, doubled and with the bottom loop folded over (see page 40). In preparing these tags, it is important to remember that both wires must pass through the hole in the metal tag, otherwise, the slight movement due to winds will cause the metal to wear through. Two wires prevent this action indefinitely. Since a small wire cuts through a zinc tag in one or two years, heavy wire must be used. Wire such as I have indicated is satisfactory. I print the necessary information on each tag with a small, steel awl, and such labels are still legible after twenty-five years. Copper, brass or aluminum would also make good tags, but these metals are more expensive. Of course, these tags may be used for small trees as well as grafts and scionwood and it is always well to do a good job of labeling all work, since many errors may result from disregard to this important detail.

In the north, the time to graft nut trees is when the cambium layer of the host, or stock, is active, which is usually during the entire month of May. This cambium layer consists of those cells lying just inside of the outer bark, between it and the woody part of the tree. When these cells are active, the inner side of the bark feels slippery and a jelly-like substance can be scraped from it. Although this is the state in which the stock should be for grafting, the condition of the scions should be almost the opposite, rather dry and showing no signs of cambium activity. The bark should cling firmly to the woody part of the scions, whereas the bark of the stock should slip off readily. Another good and fairly satisfactory rule is never to graft the stocks of nut trees until after the young leaves appear.

In grafting young nursery trees not more than an inch in diameter, the whole tree is cut off at any distance from the ground convenient to the nurseryman. Sometimes they are cut within a few inches of the ground, sometimes two or three feet. In my work, I like to keep the scions as high above the ground as I can. When the top of a stock is cut off, there is a great deal of sap pressure and the tree bleeds. It is a poor policy to attempt grafting while this is happening. Rather, one should cut the tops off, then wait for several days before inserting any grafts. Tools must be kept very sharp. A good grafting knife is sharpened on one side only, so that the blade is flat along the side which lies next to the cut made on the scion when it is trimmed. If unaccustomed to handling a knife, one can obtain more accurate results by using a small plane. I do this by holding the scion firmly in my right hand and pulling it toward me, against the cutting edge of the plane which is held in the left hand. Illustrations show how this is done.

The only disadvantage in using a plane is that one must exchange it for a knife to make the receiving cut in the stock before inserting the graft. This necessitates exposing the graft to the air for a longer time than does using a single instrument.

Spring budding is done during the same period as grafting. Bud wood is usually much larger in diameter than scionwood, for it is easier to remove buds from big branches than from wood only one-quarter inch in diameter. When budding is to be done, take along only enough wood for half a day's work, leaving the rest safely stored. A piece of wood having a bud is prepared as shown in the illustrations "A" and "B" (next page). A T-shaped slot is made in the stock to receive the bud, a process called "shield budding." This is tied in place with either string, raffia or gummed tape, as shown in "C" and "D" (next page). The bud must be free to grow, and although it may be covered completely with wax, no part of the binding material should be close to it. Since it is not necessary to cut off all the tree in budding, enough of it may remain above the bud to brace the shoot that develops. Later, it may be necessary to cut back the tree to the bud so that a callus will form and cause the wound to heal properly.