Showy and exotic orchids are the headliners at this week’s Kunia Orchid Show, but fans of bonsai will also find something of interest.

Keith Schultz of the Rainbow Bonsai Club of Oahu is leading an effort to create a bonsai “forest” in conjunction with the orchid show taking place in the Leilehua High School gym in Wahiawa.

Starting at 10 a.m. Saturday, the 60-year-old retired Marine and other club members will begin placing 21 miniature ironwood trees on a concrete slab camouflaged to resemble a natural setting. Schultz is responsible for the prep work, diagramming where each tree is to be placed, removing individual trees from their containers and wrapping the roots in sphagnum moss.

To keep the trees in place and the roots intact at the display, the bonsai team will make a sticky muck of peat moss or pine bark, potter’s clay, chopped sphagnum moss and water.

“We like that part. It’s like playing in the mud as kids,” said Schultz, who lives in Kailua.

The muck will be placed under each of the trees before they are artistically arranged on the slab in groups of three. The finishing touches will then be applied, bonsai style, with clippers.

“Once we place the trees on the slab, we may need to cut back some of the branches,” he said. “You need to be able to see all of the trees. One tree should not be hiding another.”

The roots of the forest display reach back more than 20 years to a similar exhibit of 40 ironwood trees created by a bonsai master from Japan while attending a convention in Hawaii, according to Schultz. The trees and slab were given to local bonsai sensei (master) Ed Nakanishi. When Nakanishi fell ill from cancer and was unable to care for the trees during the last couple of years of his life, they were passed on to Schultz.

“When I inherited the plants, most of them were dead,” he said. “I put the remaining live trees into growing pots to regain their vigor. Some of the larger trees that we are using are from the original forest.”

The Japanese art of bonsai involves artificially dwarfing potted trees and shrubs by regularly pruning the roots and pinching off new growth. They are wrapped in wire to produce desired shapes.

Schultz said he first became intrigued with bonsai as a teenager after reading newspaper articles on the subject. “In the beginning I learned by trial and error,” he said. “It was hard to find any books in English.”

It wasn’t until he was deployed to Okinawa with the Marines that he began to delve deeply into the hobby.

Schultz began by buying larger trees and cutting them to decrease their height and reduce the size of leaves and the space between them. “Anything over 4 feet is not bonsai, it’s a topiary,” he explained.

Those grown in shallow containers require lots of water and fertilizer.

“The smaller plants are harder to take care of because they dry out a lot faster and require more water control,” said Schultz, who has lived in Hawaii since 1991 and retired from the Marine Corps in 1997.

He received formal training from Nakanishi and California master Kenji Miyata in 1993, and also picked up tips and techniques from attending workshops at conventions. He now shares his expertise with his own students.

Rainbow Bonsai Club offers classes twice a year. Those who complete the classes are eligible to attend monthly workshops through the Bonsai Foundation Clinic. About 100 students have participated over the past four years.

Schultz orders his soil, tools and supplies from Japan. Students may purchase these items from him. He said it’s OK for beginners to buy less expensive tools such scissors, tweezers, branch cutters and pliers, but that won’t do for more devoted enthusiasts.

“If you’re in it for the long haul, it’s better to invest and get good tools,” he said. “It’s well worth it because you get what you pay for.”