How to Grow Karl Foerster Feather Reed Grass in Your Yard

Karl Foerster feather reed grass is a type of ornamental grass that has a stiff, upright growth habit. In the north, its foliage remains green into late fall, at which point it turns a golden-tan color. In the south, it is evergreen. But an even bigger selling point than its attractive foliage is its flower heads. The flower heads are pink initially but morph into a tawny color in fall. The plant is popular and grown both individually and in groups to create a screen. But Karl Foerster has benefits that go beyond its landscaping uses, including its ability to attract birds and its presence is cut flower and dried flower arrangements

Learn how to grow Karl Foerster feather reed grass, including what its sun and soil needs are and when you should cut it back.

Karl Foerster Feather Reed Grass Care

There are two main care requirements for growingKarl Foerster feather reed grass:

• Plant it in well-draining soil with proper sun exposure for your region.
• Because of its ornamental value during winter, wait until the end of winter to remove dead stalks. Cut it down to within about 6 inches of the ground in late winter prior to the emergence of spring shoots.

Light

In the north, grow Karl Foerster feather reed grass in full sun for optimal performance. But, in the south, partial sun is better; some afternoon shade will help the plant deal with the intense summer conditions.

Soil

A friable soil is best, although this grass tolerates a variety of soil types.

Water

Generally, try to keep the soil evenly moist. However, Karl Foerster feather reed grass does tolerate wet soil. This fact suggests one possible use for this ornamental grass: in plantings along the perimeter of a water fountain, where some splashing will occur.

Temperature and Humidity

While Karl Foerster feather reed grass is listed for USDA Zones 5 to 9, it can struggle with high humidity at the southern end of that range. But it is solidly cold-hardy throughout Zone 5, making it a good choice for the northern region.

Fertilizer

Karl Foerster feather reed grass likes rich soil. When planting, choose a spot where you have enriched the soil with compost. For best results, work more compost into the ground around it annually in spring.

Types of Reed Grasses and Feather Reed Grasses

Calamagrostis is the reed grass genus and Calamagrostis x acutifolia is the feather reed grass species, from which various cultivars derive, such as Karl Foerster. Other choices in reed grasses and feather reed grasses include:

• Calamagrostis x acutifolia 'Overdam':Variegated (green, with cream-colored edges) cultivar; green tints mixed into the pink color of the flower heads; more compact than Karl Foerster at just 2 to 4 feet tall
• Calamagrostis x acutifolia 'Eldorado': Variegated (green edges, with cream-gold center) cultivar; more cold-hardy than Karl Foerster (to zone 4)
• Calamagrostis brachytricha: Also more cold-hardy than Karl Foerster (to zone 4); unlike Calamagrostis x acutifolia, it is a warm-season ornamental grass
• Calamagrostis canadensis: Most cold-hardy of them all (to zone 2); but flower heads are not as attractive

Propagating Karl Foerster Feather Reed Grass

The seeds of this hybrid plant are sterile, so you can't propagate it via seed. Instead, you propagate this clump-forming grass by dividing the clumps. In fact, you should practice division at least once every three years even if you aren't interested in propagation; this keeps the plants healthier. Karl Foerster feather reed grass is a cool-season grass, so the best time to divide it is either in early spring or early fall during its active growing times. There will be enough time before the arrival of extreme weather conditions for a new clump to become established.

When dividing a clump, how many divisions (new clumps) you should try to get out of it depends on the size of the clump and the vigor of the root system. New clumps that are too small or that lack vibrant root systems will take longer to produce plants with large flower heads.

Potting and Repotting Karl Foerster Feather Reed Grass

Karl Foerster does well in containers and can serve as a focal point for an outdoor space as a potted plant. Drainage is one key to success, so make sure to use a porous terracotta pot or a container with drainage holes in the bottom to ensure the plant has ample drainage. Plant your Karl Foerster feather reed grass so that the crown rests a little above soil level, fill the pot with a soilless potting mix, and keep the soil evenly moist after potting.

Save yourself some work and start out with a pot that is a bit wider and deeper than the root system currently needs so that, when it expands, you won't have to repot right away. Just don't overdo it. Too big a pot will retain too much moisture, potentially causing fungal problems. When it is time to repot, focus once again on drainage, crown placement, and proper irrigation.

Overwintering

As far North as Zone 5, Karl Foerster feather reed grass needs no winter protection. This holds true even when you grow it in a pot, which presents a challenge for many plants because their roots, being above ground level, are fully exposed to the winds and chills that winter brings. If you attempt to overwinter Karl Foerster feather reed grass north of zone 5, apply 3 inches of mulch around its base for winter protection.

Common Pests and Plant Diseases

Karl Foerster feather reed grass has no major pest problems. One of its few disease problems is rust, a fungal disease. Rust won't kill a plant, but it does mar its appearance. Stunted growth is one result of a rust infestation. You likely have rust if you see rust-colored specks distributed on the foliage of the plant (although the color can also be brown, orange, purple, red, or yellow).

Prevention is the preferred method of dealing with rust. Because rust is a fungal disease, it tends to attack foliage that is wet. To prevent this avoid overhead watering by watering the plant at ground level and provide proper spacing so proper air circulation can keep the foliage dry. If it's too late for prevention, treat rust with a spray that contains Chlorothalonil.

Common Problems With Karl Foerster Feather Reed Grass

Other than rust disease, the main problems for this ornamental grass result from its being grown in a location where it does not receive enough sun. These problems include fewer flowers, stunted growth, and the plant flopping over. To avoid these problems, make sure Karl Foerster feather reed grass gets at least six hours of sun daily.

From: thespruce