Grafting Trichocereus cacti involves attaching a Trichocereus scion (top portion) to a compatible rootstock, such as Pereskiopsis, Myrtillocactus, or another Trichocereus, to boost growth, speed up propagation, or save damaged plants. This technique is popular among collectors and growers for producing faster results, supporting rare or weak specimens, and creating visually striking combinations.