One of the world's finest collections of Japanese bonsai trees is just outside Philadelphia, in Kennett Square, Pa.

Called the Kennett Collection, it is featured in a new photography book, "Fine Bonsai." It might be the only place you can see them. The Kennett Collection is private, owned by Doug Paul.

When Paul bought the six-acre plot fifteen years ago, he immediately dug ponds for his Japanese koi fish. It didn't take long to expand into bonsai.

"Koi and bonsai have always grown together," said Paul, wending among the creeks and waterfalls that feed his ponds, and amid his 2,000 miniature trees, most imported from Japan.

The word bonsai literally means a plant in a tray. Species such as pine, azalea, and maple are artificially dwarfed inside small pots -- their roots are regularly trimmed to keep them small. As they age, their trunks and branches twist and grow craggy with furrowed bark, while remaining only a foot or two tall. Some of these trees are centuries old.

"That black pine over there is supposedly an old Shogun black pine. It was owned by a Shogun years ago," said Paul, gesturing to a tiny tree with cascading needles. "That is over 200 years old."

Paul hires two people full-time to maintain the trees, but aside from personal friends and colleagues, the garden is rarely seen by outsiders. Many of the trees are legends in the bonsai world. Paul is the first American to have trees displayed in the Kokufu bonsai competition. The annual competitive show in Tokyo is the largest and most prestigious in the world.

"It's sort of like the Westminster Dog Show," said Paul.

"It's probably the finest collection in North America," said William Valavanis, the publisher of International Bonsai magazine and co-author of "Fine Bonsai." He helped his collaborator, photographer Jonathan Singer, gain unprecedented access to all of the best bonsai collections in the world.

"When photographers go to visit the bonsai museum in Japan, many foriegners don't respect the trees, nor the owners," said Valavanis. "They might move a tree, or move a branch, and often break trees. Damage them. You have to know how to act in the gardens."

Valavanis gave Singer a crash course in bonsai. The photographer is reknown for his botanical work, including the mammoth tome "Botanica Magnifica," for which he roamed the world photographing rare flowers. But he didn't know from bonsai.

His approach rubbed some gardeners the wrong way. Singer works very quickly, meticulously lighting and composing his shots, but letting his subjects hang loose. His flowers sometimes have dried leaves, miscolored petals, or traces of the presence of insects.

"It doesn't have to be perfect, because the world isn't perfect," said Singer.

That is anathema to many bonsai masters, who can work for decades on a single plant to make it perfect.

"I wanted to move stuff out of the way," said Paul. "Can't we prune this long shoot, or do something like that? He said, 'no, I want to get it as it would be in the garden growing.' It's a different type of experience than what I'm used to."

Bonsai is a very slow hobby. Just to bring a live tree over from Japan can take years, as FDA regulations insist imported trees be bare-rooted -- with no native Japanese soil -- then quarantined in Mississippi for over a year. Trees that survive the ordeal need years of TLC to recover.

Singer, on the other hand, works very fast. As soon as he sets up the shot, he clicks the shutter exactly once. With no backups and no second thoughts.

"What I've learned is to find the soul of the plant, quickly. And I mean quickly," said Singer. "You find it. You know it. You shoot it. And it's done. If you can't do it in one shot, you can't do it 500 shots."

In the summer of 2011, Singer traveled to Japan to shoot bonsai gardens. The owners of the gardens gave him access for a limited window of time. Singer suffers from Parkinson's disease, which restricts how long he can work in a day. It was also a few months after the devastating tsunami and nuclear accident in Japan, which caused problems with travel and electrical power.

Singer and Valavanis didn't let anything stop them.

"One reviewer said some of the photographs showed the tree when it was not ready to go," admitted Singer. "Some of these were not shot at the right time. This may not be the most perfect time to shoot -- in the summer -- for winter plants. But it's either that, or nothing."

In Kennett Square, Paul ran his fingers over a dwarfed juniper tree. "This is a shimpaku. This was not photographed, my best tree in the collection," said Paul.

The tiny tree has a slim, reddish-brown trunk snaking in frozen pas de deux with a shock of white deadwood. "You see how the live vein moves the twist," asked Paul, admiring his own private treasure, one the rest of the world may never see.