For therapeutic horticulture (TH) professionals and volunteers, we often lead with the visual beauty of the garden. However, the sense of smell offers the most direct and primitive route to the human brain. Unlike other senses, which are routed through the thalamus, olfactory information travels directly to the amygdala and hippocampus—the centers of emotion and memory (Herz, 2016).
In a therapeutic setting, intentional engagement with plant scents can bypass the "noise" of modern life, providing immediate grounding, emotional regulation, and a unique gateway for metaphorical reflection.
Why Plants Are Scented: Nature's Communication
To help participants connect with the garden, it is useful to explain why plants produce volatile organic compounds (the source of scent). Plants are not scented for our pleasure; they are scented for their own survival.
Attraction: Sweet, floral scents are "beacons" for pollinators, ensuring the next generation of life.
Defense: Pungent or "herbal" scents, like rosemary or marigold, often serve to repel herbivores or protect the plant from fungal and bacterial threats.
Communication: Plants release chemical signals to "warn" neighboring plants of stress or pests.
Scent as Metaphor in TH
This biological reality provides a beautiful metaphor for our participants: Scent is the plant’s way of expressing its needs and protecting its boundaries. In our sessions, we can ask:
"What is your 'scent' today? Are you broadcasting a need for connection/attraction, or are you feeling a need for boundaries and protection/defense?"
"Just as a plant uses scent to survive its environment, how can we use our own 'signals' to communicate our needs to those around us?"
North Carolina’s Olfactory Palette
Our North Carolina climate allows for a year-round "scent calendar." All of the following suggestions include links from the North Carolina Extension Gardener Plant Toolbox, where you can search for hundreds of scented plants. Here are some local favorites to include in your therapeutic designs:
Therapeutic use: Tactile leaves combined with scent for multi-sensory engagement.
Activities for Olfactory Intentionality
1. The "Scented Breathing" Walk
Instead of a general nature walk, lead a "scent-first" exploration. Have participants close their eyes while you bring a bruised leaf (like Rosemary or Lemon Verbena) near them.
Goal: Focus and grounding.
Activity: Use the scent as a focal point for a 4-7-8 breathing exercise. Inhale the scent for 4 seconds, hold for 7, and exhale for 8. The scent provides an "anchor" for the mind.
2. The Memory Mapping Workshop
Using aromatic herbs common in NC (Lavender, Mint, Rose), have participants smell an herb and immediately write down the first memory or color that comes to mind.
Goal: Reminiscence and emotional expression.
Activity: Create a "scent map" on paper, drawing lines from the plant to the memories it evokes. This helps participants externalize internal feelings.
3. "Boundary" Potpourri
Discuss the "defensive" scents of the garden (Sage, Thyme, Marigold).
Goal: Exploring personal boundaries and self-protection.
Activity: Participants harvest these pungent herbs to create small sachets. As they blend the herbs, discuss what "defense mechanisms" they find helpful in their own lives and how they can carry that "protection" with them. Exercise care with this activity if participants may place items in their mouths; suggested plants are non-toxic.
Conclusion
By elevating the sense of smell from a background feature to an intentional therapeutic tool, we help our participants find immediate grounding and a new language for their internal experiences. In the North Carolina garden, the air is always communicating—we just have to teach our participants how to listen with their breath.
Reference: Herz, R. S. (2016). The Role of Odor-Evoked Memory in Psychological and Physiological Health. Brain Sciences, 6(3), 22.
