3. As the visible, above-ground portion of your cactus grows, its roots will as well. As your cactus becomes larger and larger, which can take years, it may need to be repotted multiple times. However, because the transplantation process can be stressful for plants, it's important that you allow your cactus to "recover" after each time you repot it. Instead of keeping the repotted cactus in a location where it receives a good amount of sunlight, try keeping it in a shaded or partially-shaded area until its roots re-establish. Gradually re-introduce the cactus to sun over a period of a month or so.