What is Japanese Forest Grass?

Japanese forest grass is the common name of Hakonechloa macra, one of the species of ornamental grasses that originated in Japan. Rather than growing in tall, straight lines as many other grasses do, this type of grass grows in arching clumps of leaves. The clumps layer over each other to extend the plant often to a height of about 12 inches (30.5 cm), and sometimes expanding as widely as 2 or 3 feet (61 to 91.4 cm) over time. The leaves, which average about half an inch (1.27 cm) in width, are gold colored with lengthwise stripes of bright green. Japanese forest grass produces a few long, thin flower stalks around mid-summer but doesn’t generate viable seeds, and in the autumn, its leaves turn various shades of bronze or orange.

The grass first grew on the cliffs of Mount Hakone near the Japanese city of Yokohama. This natural habitat — cool, moist and partly shaded — dictates the best growing conditions for Japanese forest grass in other parts of the world. Even though it prefers partial shade, it can tolerate both full shade and sun, the main effects being that the leaves tend to turn lime green in full shade or yellow in full sunlight. The grass does, however, need consistently moist soil with good drainage, and it grows better in moderate climates than in colder regions.

Golden Japanese forest grass, or Hakonechloa macra aureola, has been the most common cultivar in North America since the introduction of this grass. New varieties have been developed with slightly different characteristics. For example, Hakonechloa macra albio striata, with green leaves and white stripes, does better in sunlight. Hakonechloa macra beni kaze, on the other hand, still prefers partial shade, but its leaves turn a bright, almost fiery red over the summer.

Japanese forest grass has gained in popularity as one of the perennial plants placed alongside walkways or used as a border with taller plants behind it. Its slow growth requires patience from the gardeners who use it, but that very quality also makes it easy to manage. Its gold and green colors, gradually shading toward red in the autumn, are used to create striking contrasts with other foliage. This explains its growth in popularity as an ornamental garden plant.