Wes Buss gingerly patted the dirt around his newly transplanted tomato plant. His hands seemed to know just what to do.

They didn't tremble. They didn't fumble. They didn't give up.

Several years ago, when his Parkinson's disease began to make it difficult for him to tend to his many gardens, Buss built sidewalks and a ramp to ease his scooter's path around the yard. But let the disease prevent him from gardening? "I'll never be ready," said the 73-year-old Twin Citian.

Buss was just the kind of person Jeannie Larson had in mind 16 years ago when she started a therapeutic horticulture program through the Minnesota Landscape Arboretum. The idea was to use plants to improve the body, lift the spirits and stimulate the mind.

Each year the number of people who have turned to Larson's therapy has grown, swelling to 5,500 last year. And Larson has learned to tailor gardening tasks to the person and the condition.

For a Parkinson's sufferer such as Buss (who attends Larson's once-a-week sessions at Struthers Parkinson's Center in Golden Valley), working with plants can free up movement and minimize depression.

"It's not like I have a one-size-fits-all program," said Larson, program manager for the Center for Therapeutic Horticulture. "I go to where a person is and then I say, 'OK, I can make this work for what your interest is.' "

Developing the program has been a personal and professional journey for Larson, who has dyslexia. She's found that being with nature helps her focus and brings her a sense of peace.

It's those qualities that can turn gardening from a pleasant occupation into a therapeutic aid, said Larson. Plant-filled environments stimulate the senses, unlike some traditional therapies, and help people engage with and concentrate on the activities they're doing.

Larson manages five consultants, all of whom have formal education in horticulture therapy-related fields, as well as about 30 volunteers. They bring programs to metro-area group homes, eating-disorder treatment centers and more. Some people drawn to the therapy are lifelong green thumbs; some are greenhorns when it comes to plants.

Four paths to healing

With each different condition, Larson considers how "four domains" of her program -- the physical, psychological, intellectual or social aspects of gardening -- can be applied to help.

For people with Parkinson's, planting can lessen the characteristic tremors.

"Working with plants, their mind gets into another topic instead of focusing on decreasing the tremor in their hand," she said.

And because Parkinson's often is accompanied by depression, accomplishing easy gardening tasks can be especially rewarding.

"I gear my programs toward success. They're dealing with very small, doable situations," Larson said.

Li-jung Lin, a doctoral student who works with Larson, said she has seen participants' outlooks transform as they work. "The plant has very special healing effects for people," she said. "When you touch it, smell it, you want to take care of it."

That's the case for Curtis Johnson, 77, a Struthers attendee. A lifelong gardener, Johnson volunteered at the arboretum for 12 years before his Parkinson's was diagnosed.

Now, he goes to Larson's sessions.

"I like seeing things grow," he said.

Seeking recognition

Horticulture therapy has faced a bumpy road to become a legitimate therapy option that insurers will support. (While some practitioners use the technique, they're usually reimbursed through physical or occupational therapy programs, Larson said.)

Larson hopes to change that with her Ph.D. research, which is meant to help standardize certification. A certification test would be "the crown jewel for insurance companies to validate this therapy," she said.

According to Larson, legitimizing the therapy could mean wider interest and use.

"Of course, I'm always hoping for that," she said. "It has such a holistic approach, and I think we're re-embracing our connections with nature."

Karlee Weinmann is a University of Minnesota student reporter on assignment for the Star Tribune.