What is the art of connecting two plants in a permanent union called?

The art of connecting two plants in a permanent union is known as grafting. This horticultural technique involves joining the tissues of one plant (the scion) to the vascular system of another (the rootstock) in such a way that they grow together as one. This process is often used to propagate varieties that do not root well or to improve disease resistance and growth characteristics by combining the strengths of two different plants.

Grafting is commonly used with fruit trees, roses, and many other ornamental plants, allowing for precise control over the resultant plant's characteristics, such as fruit quality, size, and disease resistance. The success of grafting relies on the cambium layer of both plants making contact and forming a union, which is facilitated through careful technique and timing.

Propagation refers to the broader process of increasing the number of plants through various methods, while layering is a method where roots are induced to grow while still attached to the parent plant. Cutting is another propagation method involving taking a part of a plant and inducing it to root on its own, which does not involve the union of two different plants. Each of these methods serves its own purpose in horticulture, but grafting is unique in forming a lasting bond between two distinct plant species or varieties