Japanese forest grass (Hakonechloa macra 'Aureola') is a beautiful variegated ornamental grass and slow-growing perennial that is one of the rare grasses that thrive in shady conditions. It has arching lance-shaped bright green leaves about 10 inches long, and the plant forms dense spreading mounds about up to 18 inches high and 24 inches wide.
This is a very good spreading ornamental grass for shady locations, and it works well as a ground cover in shady areas or as an accent in woodland gardens. The light-colored green and gold leaves help brighten dark areas, and it blends well with blue-flowered plants such as Jacob's ladder or blue-leaved hostas. While it is best planted in spring, it can also be planted in the fall. Just make sure not to plant during summer's dry heat.
|Botanical Name||Hakonechloa macra Aureola|
|Common Names||Japanese forest grass, golden hakone grass, hakone grass|
|Plant Type||Perennial ornamental grass|
|Mature Size||12 to 18 inches|
|Sun Exposure||Partial shade|
|Soil Type||Moist but well-drained|
|Soil pH||6.0 to 7.0; neutral to slightly acidic|
|Bloom Time||July to August|
|Hardiness Zones||4 to 9|
|Native Area||Woodland areas of central Japan|
How to Grow Japanese Forest Grass
Japanese forest grass does well when planted in any moist, well-drained soil with a good amount of humus and other organic matter. Amend the soil with compost or peat moss if your conditions are less than ideal.
Spreading mulch over the ground around the plants will help keep the soil cool and retain moisture during summer, and also will keep weeds at bay. In the northern end of the hardiness range, heaping mulch over the mounds may help prevent winter kill. Leaves may scorch in hot weather, and the plant mounds can sometimes heave upward under the effect of freezing winters.
This is a low-maintenance plant. Remove the dead foliage from the prior season's growth any time from late fall to early spring. Or, you can leave the dead foliage alone until spring to afford winter protection. Divide this perennial in spring, if desired.
Japanese forest grass prefers partial shade, such as that found in woodland areas. In cooler climates, it can tolerate more sun.
This plant prefers moist but well-drain soil, heavy with humus. Dense soils should be amended with compost or peat moss before planting.
Japanese forest grass requires frequent watering and moist soil. This is not a plant for arid conditions.
Temperature and Humidity
Cool, moist conditions are preferred, similar to the low mountain forests where the plant is native. Extreme heat or cold may kill the plant. It is reliably hardy to zone 5; some cultivars may work in hardiness zone 4.
Organic mulch provides all the nutrition this plant needs. If you do fertilize, do it in spring just after the first new growth appears, then omit any feeding for the rest of the season.
Propagating Japanese Forest Grass
Viable seeds are not produced, so this plant is normally propagated by division. Dig up the clumps in early spring, divide them into sections with a spade, then replant.
Most commonly used as a groundcover, Japanese Forest Grass is extremely adaptable to a variety of garden and landscaping uses. Plant it along a border path, around trees, or to brighten up a patio. The ornamental grass can also be grown in containers. Choose a pot that has drainage holes to prevent the soil from becoming boggy and place the pot in a shady spot. Other than that, growing the forest grass in a container is low maintenance. As a bonus, the slow-growing plant will not outgrow its container for many years, if ever.
Varieties of Japanese Forest Grass
- Hakonechloa macra 'Albostriata': The green leaves on this cultivar have thick and thin creamy white stripes. The plant is more sun-tolerant than the golden forms, and it grows faster and taller, to as much as 36 inches. It may also be more cold hardy than the other cultivars.
- Hakonechloa macra 'All Gold': This newer cultivar has brighter leaves and is more upright and spiky in form. The overall plant is smaller and grows slower.
- Hakonechloa macra 'Benikaze': With a name translating as "red wind," this cultivar is green through the summer but takes on varying shades of red as the weather cools off.