Ground CoversDecorative

How To Grow Japanese Forest Grass?

Japanese forest grass

Japanese forest grass is excellent for adding accent and ground cover to shade and woodland gardens. It is hardy, non-invasive, pest and disease-resistant, and kid and pet-friendly. Even better, it is beautiful and elegant yet easy to plant and care for. 

In other words, Japanese forest grass could be perfect for your garden. However, this is only true if you know what you are doing. For example, this plant dislikes direct sunlight, dense or soggy soil, and too much synthetic fertilizer. 

So, if you want to know how to grow and care for Japanese forest grass, read on. We will cover that in this article, along with common problems and companion plants. 

What Is a Japanese Forest Grass Plant?

Japanese forest grass is a perennial plant from Mount Hakone, Japan. That’s where its other name, “Hakone grass,” and scientific name, “Hakonechloa Macra,” comes from.

Physically, this plant looks like an arch. The long blade-like leaves rise from a crown, then cascade downward gracefully into a neat clump of leaves. The leaf colors depend on the Hakone grass variety. Generally, they are sold either striped or variegated.

Each leaf can reach 10 inches long. The Hakone grass can reach 18 inches (45.7 cm) tall and 24 inches (61 cm) wide. 

How To Grow Japanese Forest Grass?

Green japanese forest grass

Spring is the best time to plant Hakone grass. Fall is okay, too, if the weather is warm enough. As for propagation, there are two options. 

Option #1: Seeds

You probably won’t use this method because viable seeds are harder to find.

Only pure varieties of Hakone grass produce them. Plus, your plant will also take longer to establish. 

Option #2: Division

This method is easier, faster, better, and more popular. Just find a healthy Hakone grass, then follow these steps:

  1. Dig up the plant with the root. Take care not to damage the root.
  2. Divide the uprooted plant into three to five sets. Each set must have roots attached. 
  3. Plant each set of shoots in the desired locations.

How To Care for Japanese Forest Grass?

Japanese forest grass is easy to care for, especially after it gets established. Once the growing conditions are ideal, your plant will be easy to maintain. So plant your Hakone grass: 

  • in moist, well-drained, and nutrient-rich soil 
  • in partial shade 
  • within the recommended USDA growing zones 5-9.

Then practice the following maintenance tasks.

Task #1: Water As Needed

Watering can

The soil should be evenly moist but not soggy. So you will have to water frequently and moderately.

Try this method – water evenly up to 1 inch deep, 2 to 3 times weekly.

Do note that potted plants and those in hot weather need more water than average. Established plants are also more tolerant of water shortages. 

Task #2: Mulch As Needed

Mulch protects soil and plant roots. In summer, it keeps the soil cool and prevents loss of moisture and nutrient. In winter, it keeps the plant and soil warm. So spread a healthy layer of mulch around the Hakone grass.

On frosty winter days, you can spread mulch over the plant too. However, it would be best to cut back the leaves (to the crown) before doing this.

Also, you only need this measure in freezing winters. Most times, it will be enough to mulch the soil alone. The plant will protect itself by going dormant. 

Task #3: Fertilize As Needed

Japanese forest grass prefers organic manure. Fortunately, mulch provides this. You can also use peat. However, if you have to use synthetic fertilizer, use a slow-release balanced one. 

Apply after the first growth appears in spring. That should be enough for the entire season. However, potted plants need constant fertilization due to nutrient loss from leaching. For them, you may have to add fertilizer once every month. 

Task #4: Keep Your Plant in the Shade

Hakone grass performs best in partial shade, but full shade also works. The plant will develop brighter colors in partial shade and darker colors in full shade. You can use this for stylistic purposes.

There is only one rule – never place or plant Japanese forest grass in direct sunlight. The leaves will get scorched and start browning. Do note that plants in cooler climates have a higher tolerance for sunlight. 

Task #5: Prune As Needed

Japanese forest grass is a slow-growing plant, so you don’t need to prune and trim regularly. You also don’t need to add any support structure. The plant will remain neat and compact. 

The only reason to prune is to remove scorched leaf parts and dead foliage or shoots. You can also prune the entire foliage to prepare for winter or a coming growing season. 

Common Problems

Here are some common problems with Hakone grass and how to prevent or solve them.

Problem #1: Scorched Leaves

Japanese forest grass with scorched leaves

This is caused by exposure to direct sunlight. As a result, the leaves turn brown, starting at the tip.

Prevent this by keeping your plant in the shade or watering the foliage. As for correction, you will have to prune the dead ends.

Problem #2: Winter Freeze

This is when the leaves freeze, causing them to heave upward instead of cascading downward.

It is a frost problem. Prevent it by pruning the foliage and covering the crown with mulch.

Problem #3: Pest Attack

Hakone grass is highly resistant to pests and diseases.

However, you can fix pest problems by spraying the plant with pest-repellent soap and water mix.

Companion Plants

Here are a few companion plants for Japanese forest grass.

  • Flowering hostas: The blue flowers contrast nicely with various Hakone varieties.
  • Coral bells: The dark colors contrast nicely with bright-colored variegated Hakone grass varieties.
  • Sweet potato vine: For the same reasons as coral bells.
  • Hellebores: It is a great companion for golden and bright-colored variegated varieties of Hakone grass.
  • Columbine: The dark foliage and brightly colored flowers contrast nicely with multiple Hakone grass varieties. 


So, there you have it. Now, you know how to grow and care for Japanese forest grass. Remember, it is all about getting things right from the beginning.

The growing condition determines the amount of care your plant will need to survive and flourish.

So start by preparing moist, well-drained, and nutrient-rich soil. Then find a healthy plant to divide to propagate your new plant. Finally, use the maintenance tips we discussed to take care of your growing plant.

That’s pretty much all you need to know. As we said, this plant is easy to grow and care for. You just need to know how. 

Leave a Comment