We now know that both humans and plants use the language of electrical potentials to respond to a wide variety experiences. But In asking how to join in the “conversation” of plants, we need to ask what matters to them. Moreover, if we seek to make the dialogue a positive one – giving beneficial inputs instead of simply extracting outputs for our own benefit - we must ask what plants find rewarding.

Much research on plant action potentials (APs) has focused on defense responses, in response to being attacked, burned, or drowned. But we there is also one positive input for which reliably produce an AP: blue light. Blue light is the color plants use most to grow, so it’s onset triggers a system-wide response. The AP quickly activates the plant’s metabolism and respiration processes, as if producing a call-to-action: “wake up, it’s time to grow!”

Here in the Hortus, we’ve enabled visitors to use our brainwaves (our most prevalent EPs) to gift blue light to the tree across the bridge. All we need to do is pay it some attention and practice slowing our brainwaves to its slower timescale. By giving this gift to a plant, we also give a gift to ourselves. The plant’s increased respiration produces more oxygen for us to breathe… a mutually beneficial dialogue.