The Art of Growing Bonsai Trees

When Fire Lt. Mike Thornhill clocks out from a long shift at the firehouse, he retreats to his home outside Columbus, Ohio, to water his bonsai—all 100 of them. He's honed his skills in the hobby for 25 years, nearly as long as he's been fighting fires. Tiny trees fill a table by his garage. Larger ones perch on stands. A nursery of starts tucks in a side yard.

"Bonsai is a good coping mechanism," he says. "I can control this little part of the world and make it look beautiful."

Many people mistakenly assume bonsai is a species, Thornhill says, but it's actually a cultivation technique. (In Japanese, the word means tray planting.) Over the years, he's trained all sorts of trees to grow in miniature: discarded junipers, native seedlings and fancy imports. "The sole goal is to make them look natural," he says.

He points out his first project: a big-box store ficus that has developed a thick trunk, wandering roots and rounded canopy of shiny green leaves. "There's something to be said about practicing an ancient art," Thornhill reflects. "You're building nature in a container and forming this piece of sculpture."

How to Get Started

As a past president of the Columbus Bonsai Society, Mike Thornhill loves recruiting newbies at annual club shows. The community is welcoming, and meetings are a great place to shop for trees, tools, pots and supplies. "My best advice is to go to a local club and get some expert help," he says. More real talk from the pro: "Start with cheap trees because you are going to kill some."

EXPERT TIPS

A full bonsai tutorial would take a book—and Thornhill shares a few fave titles below— but here's the gist.

SELECTION Beginners should start with multiples of inexpensive trees. (At the beginning, Thornhill bought ten $20 trees each year; now he allows himself one $200 splurge annually.) For backyard trees, choose species that grow in your climate. For indoors, a ficus is a good rookie project.

CARE As with any plant, you have to know the tree's light, water and nutrient needs. Due to the small pots, regular watering is essential. Thornhill recommends a chopstick to check the soil moisture: "I carried one around the yard for three years until I learned plants' watering clues."

STYLING Pruning and wiring guide the tree's shape as it grows. (Thornhill compares the technique to orthodontia.) With time, a master can manipulate the tree to create surface roots, form deadwood and craft forest plantings.

RESOURCES Thornhill is quick to say he's still learning, even after two decades. A few of his go-to books are Bonsai by Peter Chan, The Bonsai Workshop by Herb L. Gustafson, and Ficus: The Exotic Bonsai by Jerry Meislik. The American Bonsai Society is an amazing resource for finding local clubs; tree, pot and tool suppliers; and public displays. absbonsai.org

GET IN GEAR

Bonsai enthusiasts rely on a deep kit of specialty tweezers, pliers, branch splitters, shears and other tools for shaping trees and making precise cuts. Thornhill says beginners can get started with basic pruning scissors and wire cutters.

DID YOU KNOW?

A side attraction to growing bonsai is collecting beautiful hand-built or wheel-thrown pots to house the trees. Specialty pots are always high-fired (i.e., frost-resistant). A few favorite Midwest sources: Sara Rayner of Red Wing, Minnesota; Shawn Bokeno of Cincinnati; Chuck Iker of Batavia, Ohio; Dave Lowman of Kelley, Iowa; and Rob MacGregor of Felicity, Ohio.

Bonsai Examples

SARGENT CRABAPPLE These crabapples bear showy white flowers and smaller leaves, ideal for bonsai. Thornhill grew this one from a seedling he bought for pennies from the state nursery. "All you need is time," he says.

FICUS This is Thornhill's original bonsai, 25 years old—and measuring a stately 20 inches tall. "I always tell beginners to get a ficus," he says. They aren't hardy outdoors but are happy near a window.

TRIDENT MAPLE Unlike maples you may be familiar with, this variety has a three-lobe (not five) leaf. But just like the maples you know in your yard, their fall foliage puts on a show in red, orange and yellow.

SATSUKI NIKKO AZALEA One of Thornhill's biggest splurges, this Japanese azalea has exposed roots and pink flowers in spring. Bonsai have smaller leaves, he explains, yet their blooms are often full-size.