Horticulture    

Budding and Grafting            

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Budding and grafting has been employed since the earliest times. No doubt an observation was made of a natural graft (grafts occur abundantly in nature-one has just to look) by an astute farmer who saw the possibilities and consequently attempted to employ the same methods to his/her crops. It is reported to have been thought that grafts could be made successfully to animals as well. However, the consequences of those attempts, if any were performed, are beyond the scope of this article.

The next time you get the opportunity, be mindful of grafts and, see how many natural occurrences you can spot.

What exactly does it mean to bud or graft?

"Budding", defined:

• To insert a bud, from a plant, into an opening in the bark of another plant in order to propagate a desired change of variety or appearance. Budding generally refers to the grafting of single buds. (Budding is done later in the summer when the bark on the seedling slips easily. That means that when a cut is made in the bark of the seedling it can be easily pulled away from the tissue layer under the bark. This tissue is known as the cambium layer)

"Grafting", defined:

• To unite a scion (the upper part of the graft) with a stock (the lower part of the graft) thereby propagating a plant of desired variety or appearance. (Grafting is usually done from late winter, when the plants are dormant, into early spring).

Some common purposes for budding/grafting:

• Produce a fruit tree with several varieties or a different variety.
• Produce a plant with different colors of flowers.
• Shape or change appearance (produce dwarf plants).
• Correct a defect or injury.
• Replace rootstock with one better adapted to soil or climate.

Compatibility: Not all plants can be grafted successfully. In order to produce a good graft union (the growing together of both plants) the plants should be closely related botanically (the stock and scion must be compatible).

The following rules apply:

• Plants of the same genus and species can usually be grafted, even if of a different variety.
• Plants of the same genus but of a different species may or may not unite. If they do unite the union will be of inferior quality.
• Plants of different genera are less successfully grafted.
• Plants of different families will not result in a successful graft.

Some important points in successful budding/grafting are:

• Selection of scions or buds from healthy plants.
• Proper care of specimens from collection until use.
• Sharp tools for smooth cuts.
• Good contact between cambium on the stock and scion or bud.
• Proper care of plants after budding or grafting.

• T budding
• Chip budding
• Wedge graft
• Approach graft

T Budding

• The "T" cut on the stock is made in an area free from buds. A vertical slit, in the bark, 1" to 1½" long and a top slit of ½" long (in the form of a "T") are made by inserting the knife into the trunk until it meets resistance from the wood. Just slice the bark and open it up slightly with your cutting instrument. Don't worry about exact measurements. fig.1
• The bud is cut from the donor plant by starting the cut 1" below the bud, coming up underneath, and exiting about ½" above it. Make the cuts shallow, trying not cut into the cambium tissue. View Fig.2 The resultant bud is inserted into the "T" cut on the stock. View Fig.3 The stem must then be wrapped firmly to keep the cuts closed. Budding strips or tape can be purchased for wrapping material but I've found wide rubber bands work as well. Fig.4 When wrapping take care not to cover the bud. Also, covering the area loosely in plastic to prevent desiccation may be helpful.
• Note-I've read that an upside-down "T" and appropriately cut bud will create a stronger union but I've yet to employ the method. The idea is the products of photosynthesis down through the Phloem are cut below the bud rather than above.

Chip Budding

• A budding technique which may be used whenever mature buds are available. The chip budding season is longer than "T" budding because the bark doesn't have to slip and certain species whose bark doesn't slip easily without breaking are propagated more easily using this method.
• Again there are two cuts. The 1st. cut on both stock and scion is made at a downward angle of 45 to 60 degrees to a depth of about 1/8". The 2nd. cut is made about 3/4" higher and downward to meet the 1st. cut. Fig.5 The chip created is removed and placed in the cavity created in the 2nd. plant (stock). Care should be taken to make both chips of similar size but if a significant difference in size occurs then mate up one side as close as possible.
• In chip budding there is more area of the bud exposed which requires extreme care with wrapping otherwise desiccation may occur.

Wedge graft

• The top of the rootstock is cut off horizontally, at an internode, and the stock is split vertically down the center to 1-3".
• The basal (bottom) end of the scion is cut from both sides into a tapering wedge approximately 1" and inserted into the split stem of the rootstock. Fig.6
• Again, it's important that scion and stock be of similar diameter to assure good alignment of the vascular cambia at the point of contact. Fig.7 Wrapping the graft exerts pressure that facilitates graft union formation, minimizes drying from the cut surfaces, and prevents pathogen and water entry which may cause rotting. Desiccation is further retarded by covering the graft.

Approach Graft

• The Approach Graft is used to graft two independently growing, self-sustaining plants together and the closest grafting technique to natural grafting. The terms "approach" and "inarching" are often used to describe the same procedure, however, inarching is more often used when replacing the root system and approach grafting is used when replacing the scion with a reproductively mature one. Essentially these grafts provide new stock for whatever reason. See fig. 8 and fig.9.
• Plant an adapted, growing plant close to the base of the non-adapted plant trying not to damage the root structure.
• Position shoots of about 3/8" from both plants and at the point where the union is to occur peel 1-2" of bark from each, join the two and bind tightly together.
• When the plants form a union at the graft, the top of the adapted plant can be removed above the union and the bottom of the non-adapted plant can be removed below the union thereby creating one healthy plant.

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