Green Planet Naturals, an excellent out-of–the-bag soil is also available. This gives you a strong succulent and cactus combination. Place the seeds in the soil and place them one by one. If water cannot drain, it will naturally climb higher into soil, raising its level. By adding gravel to your bottom, you can artificially raise the water table. There are many ways you can test whether your soil is staying moist at the base. It is possible to test soil moisture using soil moisture sensors.