Fiber Optic Grass

Botanical Name: Isolepis cernua aka Scirpus cernuus

Fiber Optic Grass is a fountain-like ornamental grass-like sedge with small, silvery white flowers at the tips. Its resemblance to fiber optic wire lends its common names, including Live Wire Grass.

If you like unusual indoor plants, you'll want to add this ornamental sedge to your collection. It's a fun plant to have around.

fiber optic grass, Isolepis cernua, ornamental sedgeFiber Optic Grass grows well in a container indoors or on the patio. Photo © Lawcain

Growing in a clumping mound, Isolepis cernua spills over the sides of a container as it grows, making it ideal for a tall planter or even a hanging pot. Eye-catching on its own, this decorative grass-like sedge also adds texture among a display of foliage and flowering plants.

You'll find fiber optic grass for sale in garden centers and online nurseries in spring and summer. Plants are inexpensive, and you can also buy seeds. Sowing seeds is easy (see Propagation below).

Is Fiber Optic Grass poisonous? Yes, both the plant and seeds are toxic if eaten. Keep it away from children and pets if there is any chance they may play with or ingest them. Isolepis cernua can also cause skin irritation so you may want to wear gloves when handling it.

Water generously. Don't allow the soil to dry out. Foliage will turn yellow then brown when it gets too dry. Water thoroughly and often to keep the soil at least evenly moist at all times. Fiber Optic Grass is native to marsh areas, so it doesn't mind soggy soil.

Repot in spring, moving up to a container 1 size larger every 2-3 years, or when it becomes crowded. Spring is also a good time to divide the plant, if you want.

Perennial and evergreen, this showy sedge is an easy-care house plant. Keep it warm and moist, give it sunlight, and you can expect blooms from spring through fall.

Fiber Optic Grass Care Tips

fiber optic grass, isolepis cernua, scirpus cernuus, live wire grass

Origin: Southern Europe and Northern Africa

Height: Up to 1 ft (30 cm)  

Light: Bright light to full sun

Water: Keep the soil moist or wet at all times. Constantly moist soil is needed to keep I. cernua healthy and thriving. Native to marshlands, this is one plant you can't overwater.

Humidity: Moderate room (around 40% relative humidity).

Temperature: Average to warm room temperatures (65-80°F/18-27°C) year-round. If you put this tender ornamental out on the patio for the summer, it can take the heat, but bring it back indoors when the temperature drops. It won't tolerate frost.

Soil: Peat moss-based mix, such as African violet potting mix.

Fertilizer: Feed monthly spring through fall with a balanced water-soluble fertilizer diluted by half. 

Propagation: Sow seed in spring, barely covering the seeds. Keep the soil warm (around 70°F/21°C) and constantly moist. Mature plants can be divided and potted separately.

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