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Plant Profiles / Feather reed grass 'Karl Foerster'

Photos: Wikimedia Commons

GrassesOutdoorDrought tolerantPet friendly

Feather reed grass 'Karl Foerster'

Calamagrostis × acutiflora 'Karl Foerster' · Karl Foerster grass, feather reed grass

A strikingly upright ornamental grass with feathery plumes that open pinkish-bronze and age to golden wheat. It adds height and movement to pots and borders without flopping.

Full sunLight

Weekly, drought tolerantWater

Very easyCare level

Care at a glance

Light

Full sun

ShadeFull sun

Six or more hours of sun keeps the stems upright and the plumes plentiful. Tolerates light shade.

Water

Weekly, drought tolerant

DryWet

Water regularly in its first season, then only during dry spells. Potted plants need water once or twice a week in summer.

Humidity

Any

LowHigh

Adapts to dry or humid conditions.

Temperature

Hardy, -35–35°C (-31–95°F)

CoolWarm

Very cold hardy and handles summer heat.

Growth

Moderate, upright clump

SlowFast

Grows 1.2–1.8 m tall in flower and about 60 cm wide.

Soil

Adaptable, well-drained

LeanRich

Grows in most soils, including clay, as long as it isn't waterlogged for long.

Fertiliser

Rarely

RarelyOften

Little or no fertiliser needed. Rich soil can make stems floppy.

Pet safety

Non-toxic

SafeToxic

Considered non-toxic to cats and dogs.

About this plant

'Karl Foerster' was Perennial Plant of the Year in 2001 and remains one of the most reliable ornamental grasses. It's a cool-season grass, so it starts growing early in spring and flowers in early summer. The sterile plumes stay standing through winter, giving structure when little else does.

Best spots

Sunny balconies in tall pots, screening along railings, garden borders and modern, architectural plantings.

Plant facts

Botanical name	Calamagrostis × acutiflora 'Karl Foerster'
Family	Poaceae
Origin	Garden hybrid of European & Asian species
Plant type	Deciduous perennial grass
Mature size	1.2–1.8 m tall, 60 cm wide
Growth rate	Moderate
Foliage	Narrow, upright green blades
Flowers	Feathery plumes, pink-bronze to gold
Toxicity	Non-toxic to pets
Propagation	Division in spring

Seasonal care calendar

Active growth

Flowering

Cut back

Divide

Active growthFloweringCut backDivide

Based on Southern Hemisphere seasons.

Troubleshooting

Floppy stems	Too much shade, water or fertiliser. More sun and leaner soil fix it.
Dead centre in clump	Clump is old. Divide in spring and replant healthy outer sections.
Brown leaf tips in pots	Underwatering in hot weather.
Rusty spots on leaves	Rust fungus in humid weather. Cut back and improve airflow.
Slow to start in spring	Normal for young plants; growth picks up as it warms.