Japanese forest grass Greenhills

Hakonechloa macra loves nutrient-rich soil that is:

• Humus-rich (with high organic matter content)
• Well-drained (so water does not sit at the roots)
• Constantly slightly moist

If you have heavy clay soil in your garden, we recommend improving it with compost and sand before planting to ensure good drainage.

This ornamental grass thrives best in partial shade or shade. It is an ideal plant for underplanting beneath trees or shrubs, where it creates a beautiful green carpet. Unlike variegated varieties, the 'Greenhills' cultivar can tolerate a bit more sun, but in direct midday heat, the tips of the leaves may dry out. It is important to choose a location that is protected from drying winds.

The best method of propagation is by dividing the clumps. This should be done early in the spring, just before new leaves begin to sprout (March/April). Carefully dig up the older clump and use a spade or a sharp knife to divide it into smaller sections, which you should replant immediately and water thoroughly.

Yes, it is fully hardy down to -28 °C (zone 5b), so it handles our winters without any problems. However, if you are planting young plants late in the autumn, it is advisable to cover them with evergreen branches or a layer of leaves for the first winter just to be safe. It is important that they do not sit in waterlogged soil during the winter, as this could cause root rot.

You don't need to worry at all. Japanese forest grass is a clumping perennial that does not spread through aggressive underground runners. It stays in place, and its clump only slowly expands and thickens over the years. It is very well-behaved and will not threaten neighboring plants.

Yes, and that is what makes it so beautiful! From spring to summer, the 'Greenhills' cultivar has a fresh, bright green color. With the arrival of autumn, roughly from October onwards, the leaves begin to turn warm shades of beige, orange, and gold. This effect persists even in winter on the dried leaves.

Yes, it blooms in late summer and autumn (August to October). However, the flowers are very inconspicuous—delicate panicles in brown or greenish shades that blend into the foliage. The main ornamental value of this plant is therefore its leaves and overall habit, rather than the flowers.

Japanese forest grass grows slowly at first, but once established, it is a long-lived and reliable perennial. The 'Greenhills' cultivar reaches a height of 30 to 45 cm. Its growth is cascading, with leaves arching toward the ground, creating a 'flowing water' effect.

Moisture is key for this plant. The soil should be constantly slightly moist, but not waterlogged.

• After planting: Water regularly until the plant is well established.
• In summer: Check soil moisture more frequently on hot days. Mulching around the plant (e.g., with shredded bark) significantly helps keep the soil moist and reduces the need for watering.

This grass is not nutrient-demanding. Simply provide a layer of well-decomposed compost around the base in the spring. If you prefer mineral fertilizers, you can use a standard fertilizer for ornamental grasses or perennials at the beginning of the season, but use it sparingly—over-fertilizing with nitrogen can cause the clumps to become too 'soft' and collapse.

Yes, Japanese forest grass (Hakonechloa) is an excellent choice for container gardening. Thanks to its cascading growth habit, it looks very elegant in pots and softens their edges. When growing in a container, however, ensure the substrate never dries out completely, and wrap the container in insulation or place it in a sheltered spot for the winter so the roots do not freeze.

To create a continuous carpet, we recommend planting 6 to 9 plants per m². The recommended spacing is approximately 30–40 cm apart. This ensures that the clumps will grow together over time while still allowing the plants enough space for natural growth.

Do not prune Japanese forest grass in the autumn. Its dried leaves serve an important protective function for the crown against frost during the winter, and they also look very decorative in a winter garden, especially when covered in frost. Only prune in early spring (March or April) by cutting the entire clump back to about 5–10 cm above the ground. The plant will then begin to sprout beautifully again.

Japanese forest grass (Hakonechloa macra) is generally not considered a toxic plant. It is therefore safe for gardens where dogs or cats roam. Although it is not poisonous, as an ornamental grass, it is not intended for consumption.

We have good news for you—Japanese forest grass is a very healthy plant and usually does not suffer from any diseases or pests. The only potential problem is root rot if it is planted in soil that is too heavy and impermeable, where water tends to sit.