Beautiful Japanese landscapes begin with the invisible world beneath our feet
At Tsukuba Peony Garden, some of the most important work takes place where visitors can't see it.
Since 1996, the garden in Tsukuba, Ibaraki Prefecture, has cultivated its plants without pesticides. Behind that approach is Dr. Koichi Seki, a soil specialist who describes himself as a "soil craftsman" and has spent more than three decades studying the relationship between plants, microorganisms and the soil beneath them.
His work illustrates how a beautiful landscape depends not only on what grows above ground, but also on the living environment beneath it.
The Hidden Ecosystem Around Plant Roots
The colour of a lawn, the condition of trees and the health of flowering plants all contribute to the appearance of a landscape. Each is influenced by conditions beneath the surface.
At Tsukuba Peony Garden, Dr. Seki focuses particularly on the rhizosphere, the zone of soil surrounding plant roots where microorganisms and plants interact.
Tree peonies and herbaceous peonies in bloom at Tsukuba Peony Garden. Beneath the visible landscape, plants and microorganisms interact within the soil. Courtesy of Peony Garden Tokyo in Tsukuba and Leaf Co., Ltd.
Plants supply carbohydrates produced through photosynthesis that support microorganisms, while microbial activity helps make nutrients available to plants.
The relationship between plants, roots and microorganisms in the rhizosphere, illustrating their exchange of resources.
Dr. Seki describes this relationship as a form of give-and-take, in which the health of plants is closely connected to the organisms living around their roots.
Why Microbial Balance Matters
Healthy soil is not necessarily free of harmful microorganisms.
Dr. Seki points to disease-suppressive soil, where plant diseases may be less likely to develop even when pathogens are present. Interactions among microorganisms can influence whether those pathogens cause disease.
"Good soil contains plenty of good microbes, with everything in balance," he explains.
Rather than concentrating on increasing a single beneficial microorganism, Dr. Seki emphasizes maintaining conditions in which different microbial communities can coexist.
This approach forms part of his broader philosophy of soil cultivation, although microbial balance alone does not guarantee disease-free plants.
Three Decades of Building Soil
Dr. Seki began developing his soil-building methods around 1991, experimenting with organic materials including rice bran, fish meal, soybean meal and plant residues.
His methods evolved from allowing these materials to ferment directly on the soil surface to fermenting and composting them before application.
For Dr. Seki, the process is about more than adding nutrients. It involves observing how organic materials change the soil environment and how plants respond over successive growing seasons.
The Landscape Is More Than What We See
Since opening in 1989, Tsukuba Peony Garden has developed a landscape shaped by decades of cultivation and soil management.
Its flowers and greenery form part of a satoyama setting, a traditional Japanese landscape associated with the relationship between woodland, farmland and human settlements.
Plant cycles and observation, illustrating the relationship between soil conditions, microorganisms and plant growth. Courtesy of Peony Garden Tokyo in Tsukuba and Leaf Co., Ltd.
For property owners, landscaping is often judged by visible features such as mature trees, healthy lawns and flowering plants.
Yet maintaining those features over time also requires attention to soil conditions, which influence how plants establish themselves and obtain nutrients.
This is particularly relevant to private residences, resort developments and hospitality properties, where landscaping contributes significantly to a property's character.
Dr. Seki's work offers a reminder that creating a beautiful landscape is only the beginning. Sustaining it requires continued care for the environment beneath the surface.
Dr. Koichi Seki - Garden Director Profile
Born in 1960, Dr. Seki became deeply involved in horticulture after encountering the peony cultivar Hoki. He continues to provide guidance on soil cultivation and contribute to technical development.
Further Reading:
Peony Garden Tokyo in Tsukuba (Japanese; open every year between April to May)
Purchase Thoroughbred Compost (Japanese)
