Researchers Seong-Hyun Park and Richard H. Mattson of Kansas State University say there is strong evidence that contact with plants is directly beneficial to a hospital patient's health.

The researchers studied 90 patients recovering from appendectomy. Patients were randomly assigned to hospital rooms with or without plants during their post-operative recovery periods and data were collected on the length of hospitalization, administration of drugs for post-operative pain control, vital signs, ratings of pain intensity, distress, fatigue, anxiety and room satisfaction.

The study, published in the journal HortTechnology, found patients with plants in their rooms had significantly fewer intakes of pain medication; more positive physiological responses -- lower blood pressure and heart rate; less pain, anxiety and fatigue; and higher satisfaction with their recovery rooms compared to the control group.

The study suggests that potted plants offer the most benefit, as opposed to cut flowers, because of their longevity. Nursing staff reported that as patients recovered, they began to show interaction with the plants, including watering, pruning, and moving them for a better view or light.

Indoor plants make air healthier and provide an optimum indoor environment by increasing humidity and reducing the quantity of mold spores and airborne germs, the researchers added.