Dr. Bonsai's work is never quite finished

''If you haven't killed a bonsai, you haven't grown a bonsai,'' says Littleton bonsai expert Michael Levin. (Joanne Rathe/Globe Staff)

You can ask Dr. Bonsai anything, but just don't ask him if he can bring a dead bonsai tree back to life. Even if that bonsai is an $8,500 Japanese black pine with artfully displayed gnarled exposed root.

"Of all the services I have, I don't have resurrection capabilities," says Michael Levin, coauthor of "Ask Dr. Bonsai: A Care and Maintenance Manual for the Beginning Bonsai Gardener" and founder of Bonsai West in Littleton. "It's one of the saddest things when a bonsai tree dies, but you need to just get up and keep going."

Levin himself is nursing a grapefruit tree bonsai that his mother started from seed more than 45 years ago. "It's sort of sickly right now, and you can't help but get attached to a tree because of longevity and pedigree. But the expression is, if you haven't killed a bonsai, you haven't grown a bonsai."

Bonsai, the Japanese art of growing miniature ornamental trees, is not about death, but about life. "Bonsai, in the simplest form, is just growing a tree in a pot," says Levin. "It is also about the art of pruning and sculpting trees to bring out their full potential and beauty."

Most bonsai range in price from $50 to $70 a tree, but the Littleton nursery also features a masterpiece gallery, containing trees from all over the world, and featuring works by first-generation Japanese American bonsai artists. A $14,000 Hatanaka prostrata juniper, for example, was started from a cutting just after World War II and features simple and traditional lines, a horticultural gem of elegance and grace.

But $14,000 for a tree?

"There is a fascination with how expensive bonsai can be," admits Levin. "In Japan, bonsai can sell for millions of dollars, and in America, tens of thousands of dollars. This is a fine piece of art, just like sculpture or oil painting; the difference is because it is a living tree, it continues to grow, so the piece is never finished. You can spend $4,000 on a bag at Burberrys, or on a bonsai that has been passed down for four generations and is one of the oldest trees in America and reflects real age and artistry."

How did you get interested into growing bonsai?
I have a BA in psychology and was faced with becoming a counselor for emotionally disturbed kids, which I wasn't thrilled about. I saw my first bonsai at a roadside stand in New Hampshire, and was immediately drawn to these plants. I began peddling the trees on the sidewalk in Harvard Square in 1982, and people would say, "Oh, look at the cute trees." They didn't even realize they were alive. After "Karate Kid" came out, there was more of a public recognition. I opened my first store, and it just grew from there, no pun intended.

What is it about bonsai that fascinates you?
When you start a tree, it will be with you the rest of your life, just like a child, growing and changing. You're just a caregiver, tending the tree, pruning, fertilizing, and watering it. A lot of men gravitate toward bonsai, because there are not a lot of nurturing hobbies for them. I consider myself the curator of a beautiful collection as well as an art dealer who buys and sell trees, and a farmer in a very hands-on profession.

What are some of the common misconceptions about bonsai?
People are under the impression that these trees all need to grow indoors, but in most other countries, bonsai are grown outdoors. Ficus, figs, olives, jasmines, and gardenias can all be grown in the home, but pines, junipers, and redwood trees love to be outside. Bonsai can be made out of any species of trees. It is the art of pruning that keeps them small and lovely.

Have you been to Japan?
Yes, but even in Japan, bonsai is a very small business. You might think there is a bonsai nursery on every corner, but that's not true at all. There are certain regions in Japan known for a particular artist and species of trees that grow in that area. In Japan, trees are passed down from generation to generation, and so it is an awesome responsibility.

Do you feel a certain Zen while working on trees?
Just now I'm beginning to wire a Japanese black pine that's about 60 years old. It's a 10-hour project of wiring and refining, moving branches into place to bring out the hidden beauty in the tree. It is relaxing and spiritual, something that makes you at peace with yourself while doing this work. Hours can go by, yet it feels like only minutes.

What's the oldest tree in your nursery?
It's over 400 years old. But it's misleading when you talk about the age of bonsai. They can be either started from seed or collected from a bog or mountain, dug up, and then turned into bonsai. So it all depends on the tree's origins.

Do you talk to your trees?
I don't, but I'm with them every day. And people will bring back a tree they bought 10 years ago; I won't remember the customer's name or face, but I'll remember the tree. It's like visiting with an old friend. And there is such a thing as spending so much time with your bonsai that your spouse becomes a bonsai widow. Some customers name their trees, like Twister, or ManFred, but I think that's a bit odd.

How many bonsai trees do you have in your home?
I was afraid you'd ask me that. I don't have any. Not one. I work with bonsai all day, so the last thing I want to do when I walk in the door is take care of another plant.