Rich Santoro has cultivated his backyard garden in San Jose, Calif., since 1986, creating a lush landscape that draws thousands of visitors a year. Now he’s letting the beds of tulips, daffodils, snowdrops and other bulbs grow funds and awareness for St. Jude Children’s Research Hospital.

Over the years, Santoro resisted the urging of visitors to charge admission to his garden. Some even went so far as hiding cash under rocks as they strolled through.

“I told my wife that we were missing an opportunity to raise money for a cause,” Santoro said.

A picture drawn by his son inspired him to turn those garden visits into a fundraiser for St. Jude.

Santoro’s son, nicknamed Boom, was just 6 years old in 1982 when he died from a cancer called neuroblastoma. Boom drew a picture of a rainbow while being treated at a California children’s hospital, which featured it on the cover of its tour brochure for a time. Santoro framed the picture, and hung it next to the door leading from his garage to his home.

In March, a few days before his annual garden tours were to begin, the picture fell from the wall and as Santoro gathered the picture and broken frame, the idea for his fundraiser dawned on him. Santoro and his wife would cut construction paper in the shape of tulip petals, and recreate Boom’s drawing on their garage door. Garden visitors would donate $1 for each petal until the mural was complete. He called it A Rainbow for Boom.

“I thought it was going to be a gradual thing, but before we even cut out our first tulip petal, we had raised more than $2,000,” Santoro said.

A Rainbow for Boom ultimately raised more than $10,000 for St. Jude. Even though he passed the drawing every day while going in and out of his garage, Santoro never dreamed his son’s rainbow and his own garden of blooms would have such an impact on others to support St. Jude.

“St. Jude, with its research, is trying to stop childhood cancer before it can start,” he said.