As for the cactus without roots, you don't have to hope at all. Don't throw it away in a hurry. It's still possible to save it. It's a kind of plant with strong vitality. Usually cacti can survive without roots. If it is found that the root rots or the root is cut off by people, it is necessary to clean up the rotting part in time before planting.
First of all, after the wound is treated, it can be stained with some plant ashes for disinfection and sterilization, then the plant can be placed in a cool place, put on for a few days until the wound is completely dry, and then it can be planted. Do not plant without the wound being dry, so it is easy to make the plant infected, rotten, and difficult to feed. Next let's take a look at the specific process of potting and future maintenance management.
Prepare the container and nutrient soil in advance. The container is suitable for choosing a clay basin with proper size, loose and good air permeability and drainage. Bury the cactus ball in the soil, with a depth of about one quarter of the ball. Fix the plant well, do not water it in a hurry first. It is better to wait until there is a small root at the root and then give a little water. When watering, pay attention to prevent the ball from getting wet with water. Generally do not water directly from above, but appropriate amount of water in the soil near the plant. Place the plant in a place with sufficient light and good ventilation. Under normal management, wait for a month or so to send out new roots.
