Each potted plant stain is different so it is difficult to answer this question directly (absolutely). Most likely yes, following the two step process will remove the stain left by a potted plant. Potted plant stains are usually one or a combination of dirt, "the green stuff" and fertilizer stains. The first will work to deep clean and help remove the dirt and organics. The second step will neutralize the wood and brighten any discoloration caused by contact with fertilizer that has leached from the potted plant. Sometimes potted plant stains can be stubborn and require more than one application of the cleaner and/or brightener. There is a sample test kit available if you prefer to test the efficacy of the products before you purchase enough for the entire job.