Cheyenne Garden Gossip

Gardening on the high plains of southeastern Wyoming

Bonsai are not houseplants


Japanese white pine from the National Bonsai and Penjing Museum at the U.S. National Arboretum. Courtesy Wikipedia.

Published Nov. 23, 2014, in the Wyoming Tribune Eagle

A gardener discovers bonsai are not houseplants

By Barb Gorges

Everyone has heard of bonsai, trees growing in little pots—which is the actual definition of the Japanese word.

But there is much I didn’t know.

First, don’t pronounce bonsai like the war cry that sounds like “bombs-eye,” but rather, “bone-sigh.”

Second, most people recognize bonsai as a Japanese art form, but the Japanese brought it back from China more than 1,000 years ago.

And I was thinking winter was a good time to explore bonsai (say it with me, “bone-sigh”), as a specialized type of house plant, something to do indoors.

But I was partly wrong about that.

When I called Karl Kaszuba, a friend here in Cheyenne who said he first studied bonsai as a teenager, he explained that in the fall, bonsai trees are going dormant. Shaping methods, pruning and wiring, are used when the trees are actively growing.

Bonsai soil

Karl Kaszuba, Cheyenne, Wyoming, bonsai enthusiast, scoops up a handful of the gravelly soil he uses.  Pruning the tiny trees requires the special tools shown at his workbench. Photo by Barb Gorges.

Grow bonsai outdoors, mostly

In fact, the typical bonsai (say it once more, “bone-sigh”) is a temperate-climate woody species, either deciduous, like maple (or even a flowering or fruiting tree), or coniferous, like pine.

They naturally require downtime during the winter. The deciduous trees lose their leaves. Conifers stop growing. But if brought indoors with no cool temperatures reminding them to rest, they die a slow death.

Bonsai are traditionally outdoor plants year round. That works in Japan’s more salubrious climate. Here in Wyoming, we have a couple winter options, Karl said.

The trees can be heeled in, meaning that their roots, in those tiny pots, are protected with a pile of soil, or maybe they are really well mulched. A greenhouse would be handy or, what Karl has, an unheated garage with windows, as long as it stays above freezing.

For indoor bonsai, Karl works with tropical tree species, since the climate inside our homes is similar to what they require. For beginners, he suggests a narrow-leaf ficus. It is very forgiving. If you try a technique it doesn’t like, it may suddenly shed all its leaves, but then it will forgive you and grow new ones.

One of Karl’s larger bonsai specimens is going to spend the winter in a sunny little corner next to the house with its container completely buried in mulch. It also needs protection from wind which can desiccate or kill bonsai. If you were to glance at this pine, though, you’d think it was a weather-beaten foundation planting.

That’s another thing I learned about bonsai. It comes in different sizes. Some grow in containers the size of shallow soup bowls—no wonder people think they’d be perfect on the coffee table. The Japanese have a name for each size, right up to “Imperial,” about 5 feet high. They are the bonsai stationed at the entrance to the Imperial Palace.

Bonsai is also one of the few instances in horticulture in which deadwood may be prized. The traditional Japanese aesthetic is to form the “source material” to make it look like a mature tree at the least, or a craggy old tree at best. This explains why Karl was so pleased to point out some actual deadwood on his pine.

Sources of bonsai

Speaking of source material, which is the normal plant before it becomes a bonsai specimen, where does Karl find his? It could be a pine growing out in the forest that is already showing a twisted and rugged nature. He gets permission from private landowners or permits from public land managers before digging.

But there are several nurseries in northern Colorado that carry types of plants particularly prized for bonsai, as well as the specialized tools and potting mixes.

Potting mixes are another example of why a bonsai is not a houseplant. Forget the nice loamy black soil. While every bonsai practitioner swears by his own blend, most feature a lot of pea-sized gravel. Especially sharp-edged gravel, Karl said. It makes for a lot of small, fine roots—something you want for a plant trapped in a proportionately tiny pot.

With bonsai, what would have been a normal-sized woody plant has had its branches pruned to keep it small and to fit the bonsai artist’s vision. The roots get pruned too. In fact, fast growers may get their roots pruned once a year, Karl said.

Bonsai care and feeding

This limited amount of root mass means feeding and watering these trees cannot be a haphazard affair. Unlike normal potting soil with a lot of organic material, gravel can’t hold water or nutrients well.

Bonsai need to be watered frequently. Plants can require daily watering. An irrigation system works for some folks, but Karl wasn’t happy with his attempt.

Frequent fertilizer is essential, although standard houseplant fertilizers need to be watered down. Karl has added micronutrients to his regimen, treating his plants with them once a year. He’s also experimented with adding microorganisms. Pines especially seem to require a particular fungus to help them grow well.

Karl recommends two books by the late John Naka, “Bonsai Techniques I” and “Bonsai Techniques II.”

Shaping bonsai

Every gardener does a certain amount of pinching and pruning, but bonsai specialists are trying to create a picture, something that the viewer will be able to meditate on. Bonsai is meant to be seen only from the front, unlike houseplants in the window that we keep turning so they don’t get flat on one side.

Tree branches are wrapped in soft wire and bent to train them to grow in a desired form. You probably won’t see wires on trees on display or at competitions. And yes, there are many competitions, local to international.

Like other Japanese traditions, flower-arranging and tea come to mind, bonsai has a lot of aesthetic rules. They even have names for specific tree shapes to strive for. Besides trying to keep a tree alive in a small pot, there is this artistic angle. The more Karl talked about bonsai, the more I realized it is an intellectual pursuit, even a spiritual one for some.

When I took Tyler Mason’s bonsai workshop last year at the Paul Smith Children’s Village at the Cheyenne Botanic Gardens, I wasn’t looking for an intellectual challenge. I learned how to plant a jade plant cutting in a special bonsai pot, but I haven’t been able to bring myself to prune it. I’m so happy to see every leaf growing, I can’t bear to remove any until they die.

However, I do have an old jade plant that has had a tough life. It spent years in a 2-foot high, south-facing basement window. The branches grew up to the top of the window, then bent down and back up again. It has a very rugged, gnarly look. Maybe all it needs is the right bonsai pot.

More about bonsai

  1. Thalassa Cruso, known for her books on houseplants, had a public TV show in the 1960s. In one episode, she has a bonsai expert show her how to plant, prune and wire a small tree. Thalassa struggles with all that runs counter to her knowledge of houseplants, but her guest is extremely patient. See the video at
  2. The Cheyenne Bonsai Society meets the second Saturday of the month at 9 a.m. at the Paul Smith Children’s Village at the Cheyenne Botanic Gardens, 616 S. Lions Park Dr. Everyone is welcome.
  3. Be inspired by going to the Cheyenne Botanic Gardens greenhouse to see the bonsai on display, created and donated by Pat Conrad.