How to Plant and Grow Japanese Bloodgrass

When planting this striking yet invasive ornamental where it’s not banned, be prepared to control its spread.

It's hard to deny the beauty of a clump of Japanese bloodgrass backlit by the sun. Forming an upright clump. this cool-season grass does most of its growing in the spring and fall. The leaves emerge as bright green in the spring and as the season progresses, the red color starts on the tips and progresses down the leaf blade until the foliage becomes fully and intensely red in the fall.

Beauty aside, Japanese bloodgrass is highly invasive. Although non-flowering varieties with smaller rhizomes than the species such as 'Red Baron' (Imperata cylindrica var. koenigii) and 'Rubra' (Imperata cylindrica var. rubra) have been bred to be less aggressive spreaders, in a warm climate, these often revert to the highly invasive form with all-green foliage.

Due to its invasive nature, Japanese bloodgrass is classified as a Federal Noxious Weed under the Plant Protection Act (a federal permit is needed to import it or transport it between states), which gives you an idea of how invasive it is. While Japanese bloodgrass may not be outlawed where you live, be prepared to control its spread by planting it in a container or a confined space and keeping a watchful eye on it. Or, better, to avoid any issues in the first place, select one of the suggested native grass alternatives.

Planting Restrictions

Check your state law and county regulations before purchasing or planting Japanese bloodgrass. It has been reported as highly invasive in at least 12 states (Alabama, Arkansas, Georgia, Florida, Louisiana, Mississippi, North Carolina, Oregon, South Carolina, Tennessee, Texas, and Virginia. In areas with warmer winters, this ornamental grass spreads aggressively through rhizomes and self-seeding to the point where it displaces other species.

The ban of Japanese bloodgrass includes cultivars (‘Red Baron’ and 'Rubra') because, in a warm climate, they tend to revert to the 4- to 5-foot species form with green foliage that is highly invasive, spreading by seeds and rhizomes. These rogue plants are especially invasive and should be eradicated immediately.

Where to Plant Japanese Bloodgrass

Even if you live in a colder climate where the plant is not outlawed, you need to take precautions to prevent it from spreading. Plant Japanese bloodgrass in containers or in a confined space in a rock garden or border where it cannot escape beyond your yard. In a container, use it as a thriller in combination with other plants. Choose a location with full sun.

Another consideration is the extreme flammability rating of the grass. Do not plant it within the defensible space of your home.

How and When to Plant Japanese Bloodgrass

Dig a hole about twice as wide as the nursery container and just as deep. Place the grass in the hole and make sure the root crown is slightly above soil level. Backfill the hole with original soil and gently tamp it down. Water immediately.

Space Japanese bloodgrass 18 inches apart.

Japanese Bloodgrass Care Tips

The biggest challenge is to control the spread of the grass, other than that, it is a low-maintenance plant.

Light

Japanese bloodgrass grows best and develops the most vibrant red leaf color in full sun although it tolerates light shade.

Soil and Water

The grass is highly adaptable to a wide range of soil conditions, from dry to wet and clay to sand. It does not require a particular soil acidity.

Watering is typically only required until the grass is established.

Temperature and Humidity

Although the foliage dies back in freezing temperatures, the grass is winter-hardy to Zone 5. Because of the invasive nature, do not plant Japanese bloodgrass in areas with mild winters.

Fertilizer

Japanese bloodgrass does not require fertilization. Adding nutrients to the soil is likely to spur undesirable vigorous growth and spreading.

Pruning

The sterile cultivars 'Red Baron' and 'Rubra' are not supposed to flower but they might still bloom, especially in a warm microclimate. It is key that you remove the flower heads promptly to prevent them from forming seeds, which will disperse by wind.

In the spring, cut the dead foliage back to ground level to make room for the new growth.

Potting and Repotting Japanese Bloodgrass

It is highly recommended to plant Japanese bloodgrass in a container as an effective way to control its spread. Plant it in a container by itself or combine it with other plants that have similar watering and light requirements. Fill a container of at least 6 inches in diameter with a well-draining potting mix. Make sure the container has large drainage holes. Unlike Japanese bloodgrass planted in the landscape, container plants need more frequent watering.

While Japanese bloodgrass is winter-hardy to Zone 5, the roots of potted plants need to be protected from the winter cold. Bury the container in the ground in the fall or place it inside a large container and fill the space with mulch, straw, or another insulating material.

When the roots have filled the container, repot the grass in a container at least 2 inches larger and with fresh potting mix.

Pests and Problems

Except for its invasiveness, Japanese bloodgrass has no serious pest or disease issues.

How to Propagate Japanese Bloodgrass

Japanese bloodgrass is easy to propagate by division. In the early spring, dig up the entire clump, cut it into smaller sections, and replant them at the same depth in new locations.

Native Alternatives to Japanese Bloodgrass

There are several attractive native grasses with a similar compact growth habit that you can plant instead of invasive Japanese bloodgrass: 

Northern Sea Oats

Resembling bronze-colored fish, the bobbing flat seedheads of northern sea oats are distinctive and the slightest breeze flowing through a clump of grass will rustle the dry seed heads. This easy-to-grow native grass stands 2 to 4 feet tall and grows in full sun or partial shade. Zone 3-9 

Switchgrass

Switchgrass is a tough ornamental grass that stands up to a variety of harsh conditions, adding both texture and color to a landscape. Switchgrass has come a long way from being the plain grass that dominated the native tallgrass prairies of North America. Many of the recent introductions bring longer displays of colors with varieties in glowing red and burgundy. This warm-season grass blooms in mid- to late summer. Zone 4-9

Pink Muhly Grass

Also known as pink hair grass, pink muhly grass (Muhlenbergia capillaris) makes a fine-textured addition to full sun to part shade perennial borders or cottage gardens. It has dark green clumping foliage and blooms in the fall with masses of its signature airy pink to pinkish-red flower panicles. Zone 5-11 

Bottlebrush Grass

One of the many perks of planting native grasses is that the emergence of the flower heads is something to look forward to instead of dread it, as it is the case with self-seeding invasive plant species. The bristly flower heads of bottlebrush grass(Elymus hystrix) start out as green, then mature to brown in late summer. The flower heads remain attractive into autumn. This is one of the few ornamental grasses that does well in dry shade. Zone 5-9 

Little Bluestem

Little bluestem offers gardeners an authentic tallgrass prairie plant, with a size and color made for home landscapes. This ornamental bunchgrass is native across eastern North America; there are different ecotypes depending on your region so choose one that fits your local climate. Little bluestem is a warm-season grass that greens up during the warmth of late spring, with stem bases in lavender-blue. Purplish-bronze flowers rise above the foliage in August followed by clusters of silvery-white seed heads. The foliage turns shades of bronze-orange in the fall. Zone 3-9 

Prairie Dropseed

With a mounding habit, the billowy light green leaves of prairie dropseed add a soft texture to the landscape. The leaves turn golden or orange in fall, then change to coppery brown in winter. Flower panicles appear above the foliage on slender stems in late summer. The seed heads attract feeding birds which can be observed hopping around the plants and garden looking for food and cover. Zone 3-9

Frequently Asked Questions

Is Japanese bloodgrass invasive?

Yes, the grass is invasive—even cultivars that were bred to be non-invasive have invasive potential, especially in warm climates. That's why it is prohibited in many southern states, including Florida, where it has spread to more than one million acres, displacing native plant species.

How do I keep Japanese bloodgrass from spreading?

The safest way is to combine two measures: plant it in a container so the rhizomes are confined and promptly remove any flowers before they turn into seeds.

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