Step 1. Step 1. Add succulent soil that is fast-draining to your pot. The soil should be filled in around the cactus, until the soil is back to its original state before the rot. Although this can be done, it is important that the roots are not allowed to touch the water. This could lead to root rot. Some species, such as the cactus and others, can be very healthy for cats. 1. Before you start to dig it up, mark the north-side of the cactus. For your forest cacti this is the case. Follow the same steps as for indoor plants.