How To Grow Karl Foerster Grass

Ornamental grasses provide a unique kind of aesthetic vibe in a landscape. The slightest breeze could sway the seed heads, creating a dramatic effect in your garden.

One species of ornamental grass that you’ll surely love is the feather reed grass and its popular hybrid variety, Karl Foerster, named after a German nurseryman who discovered it Hamburg Botanical Garden in the 1930s.

Karl Foerster feather reed grass is a cool-season grass that’s known to be versatile, attractive, and low-maintenance. If your location is under agriculture plant hardiness zones 3 to 9, growing Karl Foerster grass will be easy for you.

Let’s get to know this plant more.

PLANT NAME: Calamagrostis x acutiflora ‘Karl Foerster’

Other Name: Karl Foerster feather reed grass, Karl Foerster grass

Plant Type: Herbaceous perennial

Native Areas: Europe

Light Requirement: Full sun to part sun/partial shade

Watering: Average (Water when the top 2 inches of soil is dry)

Fertilizer: Low to moderate

Toxicity: Non-toxic to pets and humans

Temperature: Below 75°F (24° C)

Propagation: Division of mature clumps

Growth: Medium to fast

Soil Type: Moist but well-drained, can tolerate heavy clay

More About This Grass

Just like with other ornamental grasses, the foerster feather reed grass has an erect growth with a clumping habit. From each clump arise those green foliage and loose, feathery plumes that shift in color depending on the season.

When mature, this grass can reach a mature height of between 3 to 6 feet while spreading a width of 1.5 to 2 feet.

The feathery stalks make an outstanding display providing a vertical accent to a garden. Even with the slightest breeze, this grass will move as if dancing into the wind. From the early Summer season, the stalks have a reddish brown color which then shifts to golden tan or brown in early Fall.

Feather reed grass is very suited for mass planting. But you can also plant them as an accent plant, border plant, or as potted ornamental grass. You can also harvest the stalks and use them in fresh and dried flower arrangements.

Karl Foerster Grass Care

Karl Foerster Grass

Growing Karl Foerster grass is an easy thing to do, and luckily, it also involves little maintenance. Once established in the planting bed, it can pretty much exist on its own. So here are some requirements to get you started.

Soil

An ideal planting site should have soil that’s moist and well-draining. But since this is a versatile grass, it can tolerate a wide range of soil types including chalk, sand, loam, and even heavy clay. Soil pH is also not a problem as it will do well in acidic, neutral, or alkaline soils.

It can also withstand both dry and wet soil.

Light

karl foerster grass under full sun

When choosing a good location for planting Karl Foerster feather reed, look for an outdoor space that has enough access to bright sunlight. This grass prefers full sun with at least 6 hours of direct sunlight daily. Partial shade or partial sun conditions will also suffice as long as there are at least 2 hours of direct sun.

You can’t plant this grass in heavily shaded grasses as it won’t thrive in low-light conditions.

Watering

When it comes to watering, keep in mind that feather reed grass requires just an average amount of water. When it’s newly planted, you’ll need to water more frequently to help the roots establish deeply into the ground. Water the soil when the first two inches are dry.

Once established, you can allow the soil to dry a little bit more since this grass is drought-tolerant.

Temperature and Humidity

karl foerster grass temperature requirement

Karl Foerster is a cool-season grass variety therefore it prefers a cold environment. They mostly survive the coldness of winter and would remain a winter interest in the landscape. During the Spring season, when the temperature is below 75°F (24° C), new growth starts to flourish.

Fertilizer

When established in fertile soils, the foerster feather reed grass won’t need regular fertilization. You can just add organic mulch on top of the root zone to slowly release nutrients and that’s going to be sufficient. Too much fertilizer can lead the grass to flop which is something that we want to avoid.

mulch

But if your outdoor plant looks like it needs a little boost, you can apply a one-quarter cup of 10-10-10 fertilizer per plant once growth resumes in Spring.

Propagation

Even though it’s grass, this Karl Foerster feather reed can’t self-seed because the seeds are sterile. So the way to propagate this one is through asexual means. Once the clump has matured and grown, you can divide and separate them to plant another set of Karl Foerster grass in a new location.

You can divide one clump into two or three, depending on how thick it is. Make sure you water the newly planted clump well so it won’t dry out. The best time to propagate is during fall.

Pruning

You’ll need to cut back the feather reed grass either in late winter or very early spring. This is to give way for new shoots to grow in each clump. Pruning will also get rid of the unsightly old foliage and damage from last winter.

Feather Reed Grass Cultivars

Calamagrostis ‘El Dorado’

Calamagrostis 'El Dorado'

This variety is known for its golden variegation that runs in the middle of the green leaves. It’s also clump-forming with an average height reaching about 3 to 4 feet tall. Its plumes are pale purple in mid-summer but turn into a wheat color in fall and winter.

Calamagrostis ‘Overdam’

Calamagrostis 'Overdam'

The Overdam feather reed grass is a compact variety with an average height of only 2 feet. Its leaves are variegated with green and creamy white colors. The plumes are a combination of pinkish-purple in summer then turn grayish-pink in winter.

Karl Foerster Grass Diseases and Pests

Thankfully, the Karl Foerster grass has no serious diseases or pests, making it even easier to manage in the garden. But in some locations, this grass can be susceptible to rust fungi. To prevent this occurrence, make sure there’s enough air circulation in between indoor plants and avoid wetting the foliage.

Frequently Asked Questions

Karl forester grass has moderate to fast growth, especially if the growing conditions are favorable. However, despite its tendency to grow fast, it’s not considered invasive.

You can cut back Karl Foerster grass in late winter or very early spring before new growth begins.

Use a spade to divide the clump into two to three. Dig each clump to get the roots, then plant it in a new location. Water the newly planted grass deeply.

May nurseries offer Karl Foerster grass for planting. Check out Plantly and see some ornamental grasses being sold by our partner nurseries.

Whether you want to buy, sell, or simply reach out to other plant enthusiasts, Plantly is the right place to be!

Leave a Reply

Plantly Menu