What Is Plant Grafting?

Plant grafting is a means of asexual propagation. It is labor intensive with no guarantees of success, which can makes it expensive, but it is through grafting that nurserymen are able to produce plants that have specific favorable characteristics such as drought resistance and hardiness. It also allows them to create variations in color of blossoms and in size among the same species of plants.

Function

Asexual plant propagation is done by grafting and budding, which is when plant parts are joined from two or more plants so they will grow as one plant. When grafting, the upper part of one plant (the scion) grows on the rootstock (root system) of another plant. Plant propagation done by budding is when a bud is taken from one plant and grown on another plant. This process is used to propagate a cultivar that does not root well or when its root systems are not adequate. For grafting to be successful, the scion and rootstock must be compatible, they must be at the right physiological stage, the layers of each part being joined must meet, and the graft must be kept moist until it has healed.

History

Grafting has a history dating 4,000 years to ancient China and Mesopotamia. Around 2,000 years ago, people became cognizant of the incompatibility problems that can arise from the grafting process when they grafted olives and other fruit trees. Thomas Jefferson, while in Monticello in Virginia, wrote in his garden journal that he had "inoculated common cherry buds into stocks of large kind." This journal entry was made in 1767. Also in the 18th century, apple and pear trees were grafted in England by Thomas Andrew Knight, an English plant breeder.

Purpose

Grafting and budding are used to give plants certain characteristics. For instance, you can choose a plant whose rootstock was drought tolerant, hardy and disease resistant. You can graft or bud most woody plants, and you can even clone a different variety of plant within that specific species. Pink dogwood can be grafted or budded with white dogwood, for instance. However, you cannot graft or bud different species together.

Time Frame

There are specific times when plants can be grafted or budded. Both the weather conditions and the stage of plant growth need to be considered, as well as the species and what technique is going to be performed. December and January are the perfect time to graft flowering pear trees, whereas dogwoods should be budded in August or early September.

Reasons

Some of the reasons grafting and budding are done: to achieve disease resistance and hardiness; to shorten the height and shape of the tree, such as to create a dwarf species; to reduce the time for the first production of flowers or fruits; to achieve desirable floral or fruit characteristics.