The first sign on the long, curving driveway through towering oaks reads, "Yield to the Trees." The second sign reads, "Bonsai Lover Parking. Violators Will Be Planted."

Wielding his thinning scissors with the steady hand and intense focus of a neurosurgeon, bonsai master Chase Rosade, 82, stood in the light streaming through his greenhouse roof and clipped the 18-inch-high but fully-developed Japanese maple he had found as a seedling in 1958 on the campus of his alma mater, Delaware Valley University in Doylestown.

Had he left it in the ground, it could have grown 30 feet tall by now, 59 years into its 100-year life span.

"These aren't houseplants," Rosade said, breaking the silence in the New Hope greenhouse where he has been creating bonsai trees since 1970. "This is a horticultural endeavor. You keep pruning the roots and branches to keep a bonsai small, keep it within bounds. You water it, repot it, coddle it. It's like your dog or your cat. You don't walk away from bonsais without giving them the good graces of your care."

Rosade, who has exhibited his bonsai trees at the Pennsylvania Horticultural Society's Philadelphia Flower Show for the last three dozen years, will bring his Japanese maple, along with 15 trees on loan from fellow bonsai enthusiasts, to the 2017 show, which runs from Saturday through March 19 at the Convention Center. Instead of displaying several of his own treasured bonsais, as he has in the past, Rosade will spotlight the creations of longtime students and friends.

After working for years as a landscaper, the Allentown native traveled to Japan in 1963. There, he met bonsai master Kyozo Yoshida, spent a year as his apprentice, and fell under the spell of the delicate art that dates back to 700 in China.

"It was amazing," Rosade said. "I could not get over these plants. I didn't speak Japanese. He didn't speak English. We communicated by gesture. He didn't say, 'Prune this way.' You watch him prune and shape, and you learn by watching. I started by pulling weeds, screening soil, watering."

Finally, Yoshida let Rosade work on an overgrown tree. "A man came to the nursery and sat there all day, watching me work on the tree, pruning, wiring to shape the branches. Once in a while, he nodded his head," Rosade remembered. "Turned out it was his tree."

Slowly, he became a bonsai master himself. He opened the Rosade Bonsai Studio in 1970, and traveled the world for decades as a speaker/mentor at bonsai symposiums. At one, he met Solita Tafur, a widow who founded the Latin American Bonsai Federation, and they married. Both run monthly, all-day bonsai workshops at home and teach at international gatherings of devotees.

While Rosade rules the dozens of bonsais in his greenhouse, Tafur nurtures the tropical bonsai trees that line the windows inside the family home.

"Oh, they can't wait to go outside in late May," she said, gesturing toward her flowering ficus and japonica bonsai trees with their surreal gnarled trunks and their promise of pastel flowers come spring.

"When I move them outside, it's like taking a child to camp," Tafur said, laughing. "When they have to come inside in September, October, they tell me, 'I want to stay outside.' I tell them, 'We're in Pennsylvania. You have to come in for winter.' They punish me by losing leaves. By Thanksgiving, they've punished me enough, so they stop.'"

Back in the greenhouse, which looks like a miniature fairy-tale forest where hobbits might pop out from behind the tiny junipers at any moment, Rosade pointed to a ponderosa pine, 2½ feet high. "I found it hiking in the mountains of Colorado 30 years ago," he said. "It might have been 150 years old then. I said, 'Ah, that's going to make a great bonsai.' "

Rosade's 30 years of shaping and pruning his ponderosa pine, which can live 500 years and grow to more than 200 feet in nature, have kept it at the size he found it, fulfilling his prediction of bonsai greatness.

"A bonsai is never completely finished," he said, gently clipping his pine. "It's always changing. I enjoy working every day here. It's quiet, serene. I play classical music or jazz, and I lose myself for hours on end in trimming, pruning, shaping my bonsai trees." He looked around his greenhouse and smiled. "And I'm still learning."