Tending to plants helps to relieve stress, this is a scientific fact. But did you know that taking care of your little green friends (the leafy ones, not the extraterrestrial ones) also helps you tap into the more loving, nurturing aspects of yourself? If you don't care for them, they die -- you're learning a lot about responsibility here. You're adopting a living, "breathing" organic thing.
You've heard of people talking to their plants and how good it is for the plant - it receives more carbon dioxide from your breath, which in turn helps them with their photosynthesis. By the same token, you are gaining a great deal from your plant. Beside their release of oxygen which helps you live a healthier life, they are teaching you about the subtleties of care-giving. You are forced to become more focused on something outside of your self-absorbed ego. (If you're already a loving person feel free to disregard the previous sentence.)
You become aware of its needs: How much water does it want, how much light is it getting, etc. and this translates into your human interactions. You become aware of the needs of the people around you. So, as absurd as it may seem - plants do make you a better person