This article, which we reviewed by succulent lovers, is a guide to the best grow lights. The soil moisture content can be checked by digging into the soil one inch with your fingers. You also have the option to purchase a moisture monitor. This is easy to do indoors. However, in many parts of the world this can be difficult to do outside. Before you start walking away, however, be sure to check for water retention at the bottom. If the succulent is not growing back in color and seems to be growing up or down, it may be time to get a grow light.