3 reasons Banana Peels Should NOT be used in Orchid Care Banana peels have been known to do wonders in gardens as an organic fertilizer. Their ability to enhance flower growth is phenomenal and well-known in garden centers. Banana peels have been used for a long time as a method to avoid harsh chemical treatments which produced good organic material that both houseplants and outside garden plants need. Yet, when it comes to orchids, is fertilizing with banana peels the best way to go? Although banana peels have a high concentration of potassium, banana peels should not be used in orchid care due to 3 things: (1) the ethylene gas that ages their development, (2) the fungus that grows in the cultured banana water, and (3) the natural attraction of ants and aphids.