A study by researchers at Stanford finds that there is an optimal amount of indoor greenery for enhancing psychological well-being. Using 3D modeling, the team created virtual rooms with different proportions of potted plants, wood textures, and outdoor views. They tested how these environments affected stress, sense of restoration, and belonging in over 400 participants.

Their findings suggest that when about 20% of a room’s visual view is occupied by nature, it offers the greatest benefits — promoting calmness and a feeling of connectedness. However, when the greenery goes up to around 60%, people reported rising stress levels, feeling crowded or overwhelmed. The study underlines that while indoor plants are good for mental health, balance is key: too many plants may backfire.

In practical terms, the researchers explain that this “20% nature ratio” doesn’t require a large number of plants—just a few well-placed pots are enough to create a calming and restorative indoor environment. The benefits come not from quantity but from strategic placement, visibility, and balance with clean, open space. The study reinforces that thoughtfully curated greenery can enhance productivity, emotional stability, and overall wellness, especially for young adults and people living in compact urban homes.