When he is not trying to heal a cactus, Mr. Leblanc is planting gardens of them, like one at a home in Phoenix he decided to pop in and visit unannounced. As the owner’s Shar-Pei barked through a window, the cactus doctor climbed into the garden to check out the prickly pears, firesticks and a collection of barrel cactuses, which he called a “golden mountain” for how they glowed in the sunlight.

Mr. Leblanc does not sketch anything out when he plants a garden. Rather, he will come with a trailer loaded with plants and meditate in the space for hours, then put in whatever connects with him.

“It’s just like an artist does — you see it in your mind,” the garden’s owner, Mike Stein, said after he pulled into his driveway and saw Mr. Leblanc. “I think the proof is in the end product.”

At the job in Paradise Valley, a suburb of Phoenix, Mr. Leblanc’s crew of about a half-dozen men had spent the morning digging a trench around a cactus, slowly descending deeper into the earth. Meanwhile, the trunk of the plant was being hugged by a tow-trucklike vehicle capable of picking it up.

“This is definitely a big boy,” said Ryan Willbanks, one of Mr. Leblanc’s foremen.

The doctor’s initial prognosis was not good. The huge cactus leaned precariously, just inches from the roofline of a carport. He thought his crew would have to pick it up and replant it a few yards away, probably amputating part of an arm so it did not break off during the move.

Yet as the morning went on, the arm proved stronger than it had first appeared. Once the crew had dug enough to uncover the cactus’ ball of roots, it too proved quite sturdy.

This cactus was a “survivor,” Mr. Leblanc said. No amputation would be needed, and soon, he decided, neither would the move itself. It would need to be only straightened and stabilized.

He said the cactus had sent him a message: He saw signs of growth.

“You know, he could have fallen,” Mr. Leblanc said, marveling at the resilient saguaro, the king of cactuses. “You can tell he really wanted to be saved. He’s saying, ‘I’ve got more life left.’ ”