Hakonechloa macra Hakone grass, Japanese forest grass
Symbivit Tric (arbuscular)
Symbivit (arbuscular)Hakonechloa
The genus Hakonechloa is something of a botanical rarity. Rather than being one of many genera of ornamental grasses, it is a monotypic genus represented by a single species. It was established on the work of Japanese botanist Tomitarō Makino (1862–1957), often referred to as the "father of Japanese botany", while the valid genus name was formally published by Masaji Honda (1890–1981) in 1930. The name refers to the Hakone mountain region of central Japan, where the plant grows naturally on moist woodland slopes and rocky habitats. Its taxonomic history has been somewhat turbulent. It was once placed in the genus Phragmites among the reeds because early European botanists considered some of its characteristics similar to those of marsh grasses. Only later studies revealed that it represents a distinct evolutionary lineage within the tribe Molineae. Hakonechloa is a Japanese endemic and, although it is cultivated throughout much of the world, its natural distribution remains confined entirely to the Japanese islands.
In Japan, the species is known as Uraha-gusa (ウラハグサ, 裏葉草), meaning "grass of the turned leaves", a reference to the gently twisted blades that often reveal their undersides. For centuries it has been valued primarily for its graceful movement in the wind. Unlike most grasses, which we associate with sunshine and open landscapes, this species chose life in the dappled shade of woodland. That single characteristic made it something of a revolution among ornamental grasses. Gardeners suddenly gained a type of grass capable of brightening shaded areas much as hostas or ferns do, yet offering an entirely different texture and sense of movement. In Japanese gardens it has long been used to soften stonework, water features and path edges. In contemporary landscape design across the world, it has become one of the most respected grasses for (semi)shaded positions, combining the appearance of a miniature bamboo with an unusual ability to thrive where many ornamental grasses struggle over the long term.
When searching for the most fitting description of Japanese forest grass, the word that comes immediately to mind is striking. Its slender stems carry fresh green leaves that are remarkably soft and pleasant to the touch, typically 20-40 cm long and about 1 cm wide, often becoming longer on mature specimens. The blades are narrowly lance-shaped to broadly linear, delicately pointed, and possess a thin, almost papery texture that gives the entire plant an extraordinary sense of lightness. They are arranged alternately along the stems, which arch gracefully towards the ground in their upper portions. As a result, the whole clump develops a characteristic cascading form reminiscent of a green fountain or a stream of water pouring over the edge of a stone. This combination of delicate foliage, flowing lines and constant movement gives the plant its unmistakable character.
It is at its best when planted in larger drifts, where it forms a continuous, gently flowing mass. This is not a grass that relies on one dramatic feature. Its strength lies in the overall impression. It offers fullness, softness, airiness and perpetual motion, as even the slightest breeze sets its slender stems in motion. From August to October, airy panicles of small greenish spikelets, often flushed with purple, appear among the foliage. The flowers are relatively inconspicuous and are frequently partly hidden within the leaves, meaning that the plant's primary ornamental value throughout most of the growing season remains its elegant habit.
Japanese forest grass ranks among the finest grasses for partially shaded and shaded areas of the garden, where it creates a soft transition between shrubs, stones and herbaceous perennials. It is particularly effective beneath multi-stemmed trees and shrubs with exposed branch structure, such as maples, birches, sweetspires or witch hazels. Thanks to its cascading habit and delicate foliage texture, it resembles water flowing down a slope and is therefore especially useful along paths, beside steps, near dry stream beds and among large rocks. In Japanese-inspired plantings it blends harmoniously with clipped shrubs, azaleas, ferns and hostas, while in naturalistic gardens it softens transitions between woody plants and perennial layers. The greatest effect is achieved in larger groups, where individual clumps merge into a continuous sweep. Since it increases relatively slowly, it is often worth planting several specimens together, ideally in groups of three to five or in larger repeating drifts.
Last update: 12-10-2018; 20-09-2026
Japanese forest grass thrives in humus-rich, evenly moist yet well-drained soils. It performs best in partial shade, although it tolerates deeper shade and will also grow in sunnier positions provided sufficient moisture is available. Old foliage should be removed in late winter or very early spring before new shoots emerge. The plant suffers from few significant pests or diseases, adapts well to container cultivation provided the compost never dries out completely, and is not known to be poisonous. Extreme cold is rarely a problem, although prolonged winter wet and repeated freeze-thaw cycles may cause more damage than low temperatures alone. It is hardy to approximately -29 °C (USDA zone 5).
Most horticultural references describe Japanese forest grass as a slow-spreading, non-invasive species. Our experience has been somewhat different. In ordinary borders without landscape fabric, it forms gradually widening clumps and behaves exactly as expected. However, when confined to small planting holes cut into weed-control fabric, it may eventually produce surprisingly long underground rhizomes. We have repeatedly found new shoots emerging as far as two metres from the original plant. The young shoots are so fine and sharply pointed that they can penetrate non-woven landscape fabric with little difficulty, simply piercing through it. Although this behaviour cannot truly be described as invasive in strict sense, we strongly recommend allowing the plant more space than is commonly suggested whenever landscape fabrics are used.
