Knowing exactly why your succulent leaves are turning black and what to do to fix it can help keep your beautiful garden alive. What Is a Succulent Garden? But there IS something you can do to make a succulent bloom if it's just sitting there, sulking, with no apparent reason not to produce a prized flower spike-if it's the proper season. You can make it easier for your plants and to absorb the nutrients from the coffee grounds by brewing them. They are usually easier to maintain than more exotic plants. Their green color allows them to efficiently photosynthesize.