Many of the plants found in Japan’s great gardens are also adaptable to Oklahoma landscapes. The two countries have similar climatic conditions, with the main difference between the two areas being Oklahoma’s weather extremes. The oceans surrounding Japan tend to moderate the climate. As a result, while we use many of the same plants, we often tend to use them in a slightly different manner. For example, in Japan, Japanese maples grow in full sun, which would quickly scorch the trees in Oklahoma. Many of our common landscape plants also grow much larger in Japan thanks to rich soils and wetter summers.
Most of the mainstays of Japanese gardens are easily found in US garden centers. Trees like the Japanese maple, Acer palmatum, and the Japanese black pine, Pinus thunbergii, as well as a variety of shrubs including nandina, Nandina domestica, and the evergreen azaleas native to Japan are all readily available. We also grow a number of herbaceous plants originating in Japan, including Miscanthus grasses, Miscanthus sinensis, which are native to Japan, China, and Korea. Often, the scientific name of the plant gives its origin away, as the species names of Japanese plants are often japonica, or japonicum, or nipponicum, which contains the root Nippon, the Japanese way of saying Japan.
Of course, there are many plants commonly grown in both Japan and Oklahoma, which have their origins in other areas. One example is the ginkgo tree, Ginkgo biloba, commonly planted along the streets of Japan. Ginkgos are an ancient species of tree originating from China. You will also find native US plants such as oakleaf hydrangea, Hydrangea quercifolia, growing in Japanese gardens as well as plenty of hollyhocks, oxeye daisies, and other flowering plants from around the world.
All of these plants are excellent choices for planting in a Japanese style garden. Remember to consider sun exposure when planting the more traditional Japanese species, as most will require much more shade in Oklahoma.