How soil and time shaped Tsukuba Peony Garden
A mature landscape is easy to see. The decades of work beneath it are not.
At Peony Garden Tokyo in Tsukuba, Director Koichi Seki has spent 37 years working with the land. His experience suggests that the plants, trees and scenery visible above ground tell only part of the story.
When the garden opened, it was a more artificially divided peony garden. Over decades of planting, tree growth, pruning, replanting and soil management, it gradually evolved into a landscape where peonies and herbaceous peonies grow within a satoyama environment; a traditional Japanese landscape where woodland, cultivated land and human activity coexist.
Creating a biotope was never the original objective. Dr. Seki says it emerged as a consequence of continually improving the conditions in which the plants could grow. Over time, that process created an ecosystem capable of supporting a much wider range of life.
Beneath it all is the soil.
Looking Beyond Location and Views
For homes, second homes, resorts and estates where the landscape forms part of the character of the property, location and views are only part of the equation.
The soil beneath the property can matter too.
A mature landscape depends not simply on what is planted, but on whether the land can support those plants for decades to come.
The waterside healing area at Peony Garden Tokyo in Tsukuba, one of the world’s largest peony and herbaceous peony gardens. Decades of soil building and planting management have helped create an environment where diverse plants and wildlife coexist.
About Peony Garden Tokyo in Tsukuba - Opened in 1989, Peony Garden Tokyo in Tsukuba now has around 60,000 plants across 800 varieties. Decades of pesticide-free cultivation and soil building have also helped create a rich biotope.
What Peonies Taught About Soil
Dr. Seki’s approach to soil building began with the cultivation of peonies.
When the garden first opened, its management followed common practices at the time, including the use of chemical fertilizers and pesticides.
Peonies, however, can be particularly vulnerable to problems caused by repeated cultivation in the same soil.
As cultivation continued in the same locations, Dr. Seki saw plants begin to weaken. Some stopped flowering. Eventually, some died.
That experience led him to study soil, chemistry and soil microorganisms with specialists.
His focus shifted from one question to another:
“How do you grow the plant?” became:
“How do you create soil in which the plant can grow?”
Through years of experimentation, Dr. Seki developed his own cultivation methods and still describes himself as a “soil craftsman.”
The soil-building work he began around 1991 has since become the largely invisible foundation supporting the garden’s peonies, herbaceous peonies, satoyama landscape and wider ecosystem.
Soil Has Its Own “Health”
Dr. Seki explains soil by comparing it with the human body.
People need food to remain healthy. In much the same way, plants need healthy soil around their roots if they are to continue growing for many years.
Conceptual diagram explaining the elements of healthy soil. Courtesy of Peony Garden Tokyo in Tsukuba and Leaf Co., Ltd.
Dr. Seki identifies three elements of healthy soil:
Physical properties - water, air and the firmness of the soil.
Chemical properties - nutrients required by plants.
Biological properties - the environment created by soil microorganisms and other biological activity.
None works in isolation. Improving only one does not necessarily create healthy soil. Where plants are expected to grow for decades, the balance of the soil as a whole becomes important.
And that soil supports more than an individual plant.
Its condition connects to surrounding trees and vegetation and, in turn, to wildlife living among them.
More Than 30 Years of Building Healthy Land
Dr. Seki’s approach is not based on improving the soil once and considering the work finished.
Since around 1991, he has continually produced compost and managed the soil, adapting his methods along the way.
Materials have included rice bran, fish meal, soybean meal and plant residue.
Early on, these materials were fermented directly on the soil. The process later evolved, so they were fermented and composted before being applied.
Today’s soil is therefore not the result of a single intervention.
It has been built gradually through observation, judgment, mistakes and adjustment.
Looking back on those years of management, Dr. Seki says that by around 2008, “the soil was healthy.”
By then, the garden was already benefiting from almost two decades of accumulated soil building dating back to the early 1990s.
Dr. Seki’s daily inspection of the soil is the starting point for building the rich soil that supports the garden’s diverse ecosystem.
A Landscape Cannot Simply Be Planted
Planting trees and flowers does not immediately create a mature landscape.
Peony Garden Tokyo in Tsukuba has changed as its trees have grown and repeated pruning and replanting have reshaped the grounds.
What once had a more artificial appearance has gradually developed into the natural-looking landscape visitors see today.
Every May, the medicinal herbaceous peony fields fill with flowers, creating a seasonal display for visitors.
Cultivating Land Takes Time
For gardens, second homes, resorts and large estates where the landscape itself forms part of a property’s appeal, the planting carried out when a property is first developed is only the beginning.
The longer-term question is whether those plants have an environment in which they can continue growing for 10 or 20 years.
The foundation of that environment is soil.
Soil Is an Invisible Accumulation Within the Land
Real estate is often evaluated through things that are easy to see or measure: location, buildings, views, size and convenience.
But when the landscape contributes to the character of a property, some of what has accumulated there is much less visible.
Trees that have grown over decades, management methods developed specifically for the land, a gradually formed ecosystem, and the soil that supports it all.
These are not things that can simply be recreated somewhere else in a short period of time.
Looking at the garden Dr. Seki has cultivated over decades offers another way to think about land.
Part of what gives a place its character may lie not only in what exists there today, but in the time and stewardship that have accumulated there.
Maintaining conditions in which vegetation can continue growing for 10 or 20 years is part of creating a lasting landscape.
Beneath the garden’s peonies and herbaceous peonies is soil that has been built over decades.
From that soil, plants have grown. Around those plants, a satoyama landscape has developed. And within that landscape, an increasingly diverse ecosystem has taken shape.
For long-term property ownership, stewardship may therefore extend beyond maintaining the building itself.
It can also mean caring for the soil beneath it and the landscape that grows from it.
Koichi Seki Profile
Koichi Seki is a soil craftsman and director of Peony Garden Tokyo in Tsukuba.
Born in 1960, his encounter with the peony variety “Yoshiki” led him to become deeply involved in plant cultivation.
After Peony Garden Tokyo in Tsukuba opened in 1989, he began developing soil-building methods focused on soil microorganisms and organic matter.
Drawing on more than 30 years of experience in soil improvement, he was also involved in developing “Thoroughbred Miho,” a fermented compost made primarily from racehorse manure.
In March 2022, Dr. Seki completed a doctoral program in agriculture at the Graduate School of Tokyo University of Agriculture and Technology.
He continues to work on soil-management instruction and technical development.
Further Reading
Buy your own thoroughbred compost here (Japanese only)
