What to put in the bottom of an outdoor planter without drainage holes?
Ways to prevent excess water from killing plants You may have heard that gravel or broken pieces of pottery are a great way to promote adequate draining. Along similar lines, many garden centers will sell clay pebbles to place at the bottom of a container for proper drainage. One such debunked garden habit is adding rocks or gravel to the bottoms of pots and planters in an effort to improve drainage. However, this practice has been shown to be more problematic because of the collection of stagnant water and pushes the saturated water table layer up; increasing the risk of root rot.