Does it need a lot of water?

It prefers moderate moisture during the growing season but likes to dry out a bit once established.

Will it spread on its own?

Yes, it often self-sows readily in favorable garden conditions.

Plant guide

Western blue-eyed grass.

Sisyrinchium bellum

Pronounced sis-ih-RING-kee-um BELL-um

Also known as western blue-eyed grass

This charming perennial is a member of the iris family that produces lovely violet blue flowers. It is a wonderful addition to native gardens and meadows. You will find it thrives in sunny spots with well draining soil.

At a glance

Care level: Easy
Plant type: Perennial
Light: Full sun to partial shade
Indoor light: Direct sun
Water: Every 7 to 14 days
Mature size: 1 to 2 feet tall
Growth rate: Medium
Hardiness: USDA 7 to 10
Bloom time: Mid to late spring

Care

Keep the soil consistently moist during the growing season but avoid letting it sit in soggy conditions. Watch for yellowing leaves which often signal poor drainage or overwatering. Deadhead spent blooms to encourage a second flush of flowers.

Watering: Water when the top inch of soil feels dry to the touch.
Feeding: Apply a balanced liquid fertilizer once during the spring.
Pruning: Cut back the browning foliage close to the ground in summer, after the seeds ripen and the plant goes semi-dormant.
Repotting: Repot only when the plant becomes root bound or needs division.
Soil: Well draining sandy or loamy soil
Soil pH: 6.0 to 7.5
Temperature: -10 to 35°C
Humidity: 30 to 60%
Drought tolerance: Moderate
Lifespan: Perennial, typically 3 to 5 years.
Deer and rabbits: Moderate

Signs it needs repotting

Roots growing out of the drainage holes.
Water sitting on the surface for too long.
Plant growth slowing down significantly.

Safety

People: There are no significant reports of toxicity in humans, but it is best kept away from curious mouths.
Children: The thin, grass-like leaves can be sharp, so keep an eye on small children handling them.
Edibility: This plant is not considered edible and should not be consumed.

How to identify it

Violet blue star shaped flowers
Narrow grass like foliage
Clump forming growth habit
Yellow centers on petals

Height: 0.15 to 0.4m
Spread: 0.15 to 0.3m
Leaves: green, blue-green, evergreen
Flowers: blue, violet, 1 to 2cm

Problems to watch for

Root rot · This occurs when the soil stays too wet for too long.

By symptom

Plant problems by symptom

Check your western blue-eyed grass from a photo

Pocket Botanist looks at a photo of your plant and tells you what's wrong and what to try first.

Growing it

Propagation: division, seed
When to plant: fall, spring
Overwintering: In colder regions, provide a light mulch to protect the roots from deep freezes. Ensure the crown stays dry to prevent rot during winter rains.
In containers: It grows very well in pots, provided you use a well-draining potting mix and a container at least 15 cm wide.

Division

1. Dig up the clump in early spring.
2. Gently pull the root mass apart into smaller sections.
3. Replant immediately in well-draining soil.

Seed

1. Collect dry seed pods in late summer.
2. Sow seeds in pots during autumn.
3. Keep moist until germination in spring.

Plant in groups of three or more to create a natural meadow effect.

Grows well with

California Poppy · They share similar water and sun requirements in meadow settings.
Meadow Barley · This grass provides a naturalistic backdrop for the blue flowers.

Similar species

Yellow-eyed Grass · It is a close relative with similar growth habits but yellow flowers.

Science

Family: Iridaceae
Genus: Sisyrinchium
Order: Asparagales
Class: Liliopsida
Native range: Western North America, primarily California.
Conservation: It is common in its native range and not currently of conservation concern.

It thrives in open grasslands and meadows where it competes for light with low-growing annuals.

Value to wildlife: nectar source
Pollinators: bees, butterflies
Uses: rock gardens, meadow plantings, container gardening

Through the year

JFMAMJJASOND

Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 6/9
Light: 7/9
Temperature: 6/9
Moisture: 4/9
Nutrients: 3/9

Taxonomy resolved against GBIF.

Questions people ask

Does it need a lot of water?: It prefers moderate moisture during the growing season but likes to dry out a bit once established.
Will it spread on its own?: Yes, it often self-sows readily in favorable garden conditions.

Where the name comes from

The common name Blue-eyed Grass refers to its bright blue flowers and grass-like foliage, while the scientific name Sisyrinchium bellum translates to beautiful pig-snout.

Good to know

The flowers typically close up in the afternoon or on cloudy days.
It is a classic choice for California native plant gardens.
The genus name comes from Greek words meaning pig and snout, though the connection is unclear.

Keep your western blue-eyed grass growing

This page is a general guide. Save your plant in Pocket Botanist and you get care reminders timed for this plant, plus a care history that shows what worked.

Get the app

This guide was generated with AI on October 19, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.