Japanese Forest Grass Hakonechloa macra

Japanese Forest Grass is an ornamental, shade-loving, deciduous perennial grass. Its habit is dense, arching, spreading, cascading mounds of grass that serve as a ground cover. It has arching, linear to lanceolate, bright green leaves that are about 10 inches long and 3/8 inches wide. The leaves have a blush of red to pink in the fall. During the winter the plant dies back to the ground. Flowering occurs in mid to late summer in the form of airy sprays of greenish-yellow flowers that are often hidden by the foliage. 

This grass is native to Japan, and it is found in the moist mountains of central Japan along wet rocky cliffs and moist woodlands. 

The genus name Hakonechloa is derived from the name of the mountain, Mt. Hakone, which is found in Japan. The word chloa is Greek and means grass. The specific epithet, macra, is derived from Greek and means large.

Hakone grass requires rich, consistently moist, well-drained soil. It tolerates part to full shade, particularly in hot summers, and gives the best color intensity, especially in the variegated forms, when shielded from full sun. The leaves may scorch in the heat if moisture is inconsistent. This grass will not grow in poorly drained soil, heavy clay, or very dry soils. It grows best in cool summer climates, and it may not tolerate the hot summers of the southern United States, such as zones 8 through 9. It is tolerant of urban pollution, deer resistant, and black walnut tolerant. It is best propagated by division in the spring. It is slow-growing, and it may take years until the division of the plant is required. The foliage should be cut back to the ground in late winter or early spring. 

Japanese Forest Grass has soft rich green foliage, but many variegated cultivars are available with white, green, or gold striping. This ornamental grass resembles bamboo and spreads by rhizomes and stolons but it is not considered to be invasive.

This ornamental, perennial ground cover may be used as an accent in a shady woodland garden or serve as a border along a shaded path or walkway. It is an excellent plant for all shaded locations and is attractive when planted on slopes or sprawled over rocks. 

Seasons of Interest:

Bloom: Summer    Foliage: Spring, Summer, and Fall

Quick ID Hints:

• ornamental, shade-loving, perennial grass
• arching, dense, spreading, and cascading mounds of grass
• bright green, linear to lanceolate leaves meaning 10 inches long and 3/8 inches wide 
• yellowish-green wispy flowers bloom in mid to late summer and are often hidden by the foliage

Insects, Diseases, and Other Plant Problems:  The Japanese Forest Grass is generally insect and disease free.  In hot climates, the leaves may scorch if there is inadequate moisture. Root heaving can occur during winter frosts. Apply a thick layer of mulch over the crowns of the plant before winter to prevent this problem. 

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.