Calamagrostis

( ka - la - ma - GROSS - tis )

At-A-Glance Information

This genus of perennial grasses is also called Reed Grass (or Reedgrass), and includes species of sturdy, clumping grasses native to Eurasia. These grasses produce feathery plumes of flowers that are long-lasting and can also be used in cut flower arrangements. These are long-lived grasses, and are typically used for a dramatic effect in mixed beds and borders, combining well with other perennials like Coreopsis, Echinacea, Liatris, and Rudbeckia. They are popular in prairie, meadow, and natural landscapes.

calamagrostis Species and Varietals

The genus Calamagrostis is a member of the plant family Poaceae, and includes around 260 species. The best growing zones for Calamagrostis are USDA hardiness zones 3-9, though this varies somewhat depending on the species cultivated. For more information, see the species descriptions below.. To find your zone, click here: Zone Map.

Calamagrostis x acutiflora (Feather Reed Grass)
These plants do well in USDA hardiness zones 4-9. This hybrid group is known mainly through its evergreen to semi-evergreen varieties, which are listed and described below:

'Avalanche'
To 4 feet tall with white banding down the center of each leaf. Flower plumes rise 2 feet above the rest of the foliage, topping out at 6 feet tall, and start reddish-brown, maturing to golden.

'Eldorado'
With gold-green foliage with a delicate texture. Best in partial shade in warm climates. To 305 feet tall with 4-6 foot tall flower plumes.

'Karl Foerster' ('Stricta')
Forms an erect, arching clump of narrow bright green leaves that reach about 2-3 feet tall. Clumps spread to about as wide. Flower stems reach 6 feet tall and appear in late spring and summertime.

'Overdam'
Similar to 'Karl Foerster', except foliage is white-variegated. This variety needs partial shade in summertime in warmer regions.

Calamagrostis brachytricha (Fall-Blooming Red Grass)
This species is deciduous and forms a clump of upright, arching foliage up to 2.5 feet tall and 2 feet wide. Flower spikes appear in early summertime, rising about 1.5 feet over the rest of the foliage. Great grass for partial shade, and does well in container plantings. Best in USDA hardiness zones 4-9.

Caring for calamagrostis

Plant Calamagrostis, or Feather Reed Grass, in a place in the landscape that receives full sun; ideally, they appreciate between 6 and 8 hours of sun each day. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 5.5 and 7.5 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these plants perform well in consistently moist soils; as a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Irrigation once or twice a week during the dry months of the year is sufficient.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flower spikes to neaten up the appearance of plants and encourage reblooms. Seed heads can also be left on their plants over the winter months to provide height and interest. In early springtime, cut back clumps low to the ground before new growth begins to rejuvenate for the season. Every few years, especially if these grasses are grown in containers or tight border areas, they will need to be divided to avoid becoming overcrowded. For instructions on how to successfully divide Feather Reed Grasses, consult the Propagation section below. Calamagrostis grasses typically last for between 3 and 10 years in the landscape before needing to be replaced.

Caring for Calamagrostis in Containers
Calamagrostis is commonly grown in the ground, but can also be grown in containers on patios and walkways. Choose a large container that is at least a 5-gallon size to accommodate the plant's mature root ball. Ensure that the container has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite. Top soil with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new container. At maturity, they will need more water than their in-ground counterparts. As a general rule of thumb, water whenever the top two inches of soil feels dry to the touch. The appearance of these grasses can be improved by removing any dead growth in early springtime. Needs to be cut back to between 6 and 10 inches tall in late winter or early springtime at least every few years to encourage new foliage to grow and to keep plants growing vigorously. Every few years they will need to be divided to ensure ongoing health. For instructions on how to successfully divide Calamagrostis plants, see the Propagation section below.

Harvesting Calamagrostis
In addition to being wispy additions to landscapes, these grasses are also cultivated for their cut flowers, which are used in both fresh and dried arrangements. They add airy texture and height, and are typically harvested in mid summer to early fall. Foliage color becomes most vibrant at this time of the year. Use a sharp, clean pair of pruning shears or snips to avoid damaging stems and prevent the spread of disease. Cut at the base of stems, and immediately drop them into a bucket of cool water. Fresh stems have a vase life of about two weeks. To dry stems, bunch them and hang them upside down in a cool, dark, dry area after harvesting. Once completely dried, handle with care to avoid breaking the brittle stems. They can be added to long-lasting dry bouquets, wreaths, or used in other floral crafts.

Propagation

Calamagrostis, or Feather Reed Grass, is best propagated through division. To propagate your Feather Reed Grass, follow the instructions below:

Propagating Calamagrostis by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in early spring or early fall. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
Separate the removed patch of grass into sections using a sharp, clean knife or trowel. Ensure that each division has a healthy root system and a few shoots. Any dried out areas with dead roots can be tossed in the compost.
Prepare your pot(s) or new planting site(s) with well-draining soil and compost and work it in. Water thoroughly, and then plant divisions.
Keep soil consistently moist as the newly-planted divisions establish strong root systems in their new home. Provide regular waterings, especially during dry spells.