How to Grow Sisyrinchium Plants

Guide to Growing Blue Eyed Grass

Members of the Sisyrinchium genus can be either hardy or half hardy perennials, and reach an height of between 30 and 90 cm (1 to 3 feet).

Sisyrinchium plants bloom from spring to summer and carry small star shaped flowers atop long stems; these may be blue, yellow, purple or white.

The main common names for Sisyrinchium plants is the Blue Eyed Grass.

Sisyrinchium Species and Cultivar Types and Identification

Sisyrinchium bellum: Western Blue-eyed grass, Californian Blue-eyed grass

Sisyrinchium bellum, Californian Blue-eyed grass
Sisyrinchium bellum, the Western Blue-eyed grass, photograph by John Rusk; CC.

Sisyrinchium angustifolium: Narrow-leaf blue-eyed grass

Sisyrinchium angustifolium
Sisyrinchium angustifolium, the Narrow-leaf blue-eyed grass, photograph by Melissa McMasters; CC.

Sisyrinchium angustifolium: Cv. 'Lucerne'

Sisyrinchium angustifolium lucerne
Sisyrinchium angustifolium 'Lucerne' cultivar, photograph by Andrey Zharkikh; CC.

Sisyrinchium campestre: Prairie blue-eyed grass, White-eyed grass

Sisyrinchium campestre Prairie blue-eyed grass
Sisyrinchium campestre, the Prairie blue-eyed grass, image by Joshua Mayer; CC.

Sisyrinchium montanum: American blue-eyed grass

Sisyrinchium montanum American blue-eyed grass
Sisyrinchium montanum, the American blue-eyed grass, photograph by Yellowstone National Park; CC.

Sisyrinchium albidum: White blue-eyed grass

Sisyrinchium albidum White blue-eyed grass
Sisyrinchium albidum White blue-eyed grass photograph by Frank Mayfield; CC.

Sisyrinchium idahoense: Idaho blue eyed grass

Sisyrinchium idahoense Idaho blue eyed grass
Sisyrinchium idahoense, the Idaho blue eyed grass, photograph by Jim Morefield; CC.

Sisyrinchium striatum: Pale yellow-eyed-grass, Satin flower

Sisyrinchium striatum Satin flower
Sisyrinchium striatum Satin flower photograph by Rob Hodgkins; CC.

How to Grow Blue Eyed Grass / Sisyrinchium

It is best to first sow the seeds of Sisyrinchium plant species such as Blue Eyed Grass in flats in the autumn (for spring sowing see further down the page).

The Seeds should be sown at a depth of 6 mm (1/4 inch). The flats should then be wrapped in a plastic bag and placed in the fridge for three weeks. The flat should then be sunk into the ground in a shady part of the garden and covered in glass.

The Blue eyed grass seeds should take anything from one to six months to germinate.

Sisyrinchium cuspidatum
Sisyrinchium cuspidatum by Dick Culbert.

Once the seedlings emerge, transplant them into a sunny part of the garden that has a slightly acidic soil (pH 5 to 6.5) that is moist and fertile. Depending on the species size, plants should be spaced 10 cm (small) to 40 cm (large) apart.

Caring for Sisyrinchium

Blue eyed grass and other Sisyrinchium plants require only a little looking after; they like a moist soil so water frequently and do not allow the soil to dry out. Once they have finished blooming cut back the stems to ground level.

As plants may become invasive it is necessary to remove any plants that are not wanted.

If you require more plants and do not want to grow Sisyrinchium from seed then they can be propagated by division in the spring.

Sisyrinchium Growing and Care Guide

Common Names: Blue-eyed Grass.
Life Cycle: Hardy perennial. Half-hardy perennial.
Height: 6 to 36 inches (15—90 cm).
Native: Americas.
Growing Region: Zones 3 to 10.
Flowers: Spring through to summer.
Flower Details: Blue, white, yellow, purple. Simple. Star-shaped, often with a sharp point. Small. Often clustered. Upright stems.
Fruit: Small red berries. Summer through autumn.
Foliage: Herbaceous. Grass-like (though not a true grass). Long. Thin. Green.

Sowing: Seeds: 1/8 inch. Germination time: one to six months. Spacing 4 to 16 inches (10—40 cm).
Seed: Method 1: Seeds should first be sown into flats in the autumn. Next sink the flat into the ground in an area that offers shade, preferably close to a wall that faces north. Provide a glass/plastic covering. Keep an eye on the flats to ensure that the soil remains moist. Bring the flats indoor at the beginning of spring and keep at 50°F (10°C). Transplant seedlings following the last frost or in the autumn.
Seed: Method 2: In the spring, fill a container with moist growing medium, then sow seeds. Wrap the container in a large plastic bag, and then stratify by refrigeration for three weeks. Next bury the container as described above. Once seedlings emerge transplant to their final location.

Requirements and care: Full sunlight for best results, or partial shade. Average to good drainage. Acidic soil pH 5 to 6. Fertile and moist soil. Regular watering whilst in the growing season.
Deadhead to prevent self-seeding in environments where it may grow aggressively. Cut back to the ground once all flowering has completed. Winter mulch. Leaf mold or compost mulch.
Propagate: by dividing in the spring in cooler areas or the autumn in warmer areas. Self-seeds freely.

Family: Iridaceae

Closely Related Species: Fressia, Crocus, Iris, flag.

Miscellaneous: The genus is named after the Greek term for Barbary nut iris. May become invasive.

Common Questions

How many members does the Sisyrinchium genus have?

The Sisyrinchium genus, commonly known as Blue-eyed Grass, contains about 150 species.

Do members of Sisyrinchium make a good garden or landscaping plant?

Yes, Sisyrinchium makes a charming addition to gardens with its grass-like foliage and small, star-shaped flowers.

Which Sisyrinchium species are most frequently grown by gardeners?

The most commonly grown species is Sisyrinchium angustifolium, also known as Narrow-leaf Blue-eyed Grass.

Are members of the Sisyrinchium plant genus fragrant?

While not particularly known for their fragrance, Sisyrinchium species are admired for their delicate, attractive flowers.

What is the perfect location to grow Sisyrinchium?

Sisyrinchium prefers full sun to part shade and well-drained soil. They are excellent for borders, rock gardens, and naturalized areas.

Is Sisyrinchium invasive in the USA, if so in which states?

At present, Sisyrinchium is not listed as invasive in the USA. Always consult local guidelines for the most up-to-date information.

How do I remove Sisyrinchium plants from my garden?

To remove Sisyrinchium, dig up the entire plant including the root system to prevent regrowth.

Summary

The Sisyrinchium genus is made up of perennial plants native to the Americas. Despite their common name, they are not grasses but are part of the iris family and are recognized for their grass-like foliage and small, star-shaped flowers.

Grow Sisyrinchium from seeds or division, usually in spring. They thrive in full sun to light shade and prefer well-drained soil. Regular watering is required, particularly during dry periods, and deadheading can help to encourage a longer flowering period.

I hope that you enjoyed this guide on how to grow Sisyrinchium. You may also enjoy the following growing guides: How to grow Freesia and Crocus.