What is Blue Eyed Grass?

Learn more about the blue eyed grass including its common types, how they reproduce and grow, what it looks like, and how they are being used. We've also added some tips on how to take care of these wonderful perennials.

Amazing violet flowers of the blue eyed grass plant with a blurry grass background

Genus Sisyrinchium

The genus sisyrinchium consists of many species of annual and perennial flowering plants, known as the blue eyed grasses. They are a prominent plant species that occurs all over North America, either as a wild plant or as a cultivated landscape plant.

These plant species are part of the iris family (Iridaceae) and are not actually true grass, but are monocots. A monocot is a grass or grass-like flowering plant, wherein each individual seed only contains one single embryonic leaf.

Blue-eyed grass is well known for being easy to care for, and for its lovely little periwinkle flowers that seem to stare at you with their little yellow eye. (This yellow eye simply being the corolla of the flower).

There are so many wonderful types of flowers out there, and we’ve gone over a great many of them to help educate the masses about the proper care and general information about different flower types. So whether you’re planning for your cottage garden or you’re trying to brighten up your balcony, you’re sure to find the perfect candidate in this wonderful flower article series.

What are Some Common Types of Blue Eyed Grass?

Narrow Leaf Blue Eyed Grass (Sisyrinchium Angustifolium)

Looking sideways at stems of the narrowleaf blue eyed grass plant with a blurry yellow field background

Narrow leaf blue eyed grass, or common blue eyed grass, is the most common and widespread of the genus sisyrinchium. It is extremely common all over the eastern United States, and can be found in low woodlands and along shorelines.

Strict Blue Eyed Grass (Sisyrinchium Montanum)

Close up shot of a bright purple western blue eyed grass flower with blurry blades of grass in background

Strict blue eyed grass can also be referred to as American blue eyed grass or mountain blue eyed grass. This plant also grows all over North America, but at higher elevations.

This grass is known to bear an extremely striking violet blue flower, with fields spanning very large areas.

Western Blue Eyed Grass (Sisyrinchium Bellum)

Looking down at an incredible light violet flowers with yellow centre of the blue eyed grass plant

Western blue eyed grass can also be referred to as California blue eyed grass. This plant is very common in California, Oregon, and the Sierra Nevada.

These plants prefer to grow in grasslands and woodlands, though they are able to grow up to elevations of 2400 meters above sea level.

These are a taller species of grass, sometimes achieving heights of 24 inches, with flower colors ranging from white, to blue, to violet.

Prairie Blue Eyed Grass (Sisyrinchium Campestre)

Cute bunch of light blue flowers with yellow eyes of prairie blue eyed gras plant growing in the grass

Prairie blue eyed grass can also be referred to as white eyed grass. This plant is native to the central United States, and is the most drought tolerant of the genus.

This plant is slightly different from the others as it will bear flowers that are either pale blue or white. Stems are also shorter, growing to an average of 10 inches in height.

What does Blue Eyed Grass Look Like?

Flowers

Depending on the species, blue eyed grasses will bear flowers that are very small with 6 petals. The differences lie in the color of the flowers, that can range from white, to pale blue, to deep blue, to striking violet.

Flowers also have a striking yellow eye in the centre of the flower, otherwise known as the corolla. These flowers are known for being star shaped, giving it the common nickname of “star grass”.

*A cute aspect of these flowers are that they close their eyes at night time, and open them back up again in the morning! The first pop their heads out in the early spring.

Super close up shot of a purple blue eyed grass flower with a yellow centre and stamen

Leaves/Stems

Blue eyed grass has foliage that acts both as a leaf and as a stem. These leaves are very tall and narrow, like a blade of grass. A leaf will usually be 1/8 of an inch wide, and anywhere from 10-20 inches in height.

Each individual flattened leaf flowering stem each comes from an individual seed, and each leaf will bear a flower at the end of it. These are unbranched stems.

Growth Pattern

Blue eyed grasses grow in clumps of long and slender foliage. These clumps are comprised of wiry stems topped with beautiful blue flowers. Grass-like leaves can spread over a wide distance and create a large patch.

Side view of blade like grass stems of the flowering plant blue eyed grass with purple flowers in bloom

How does Blue Eyed Grass Reproduce?

Blue eyed grass is a herbaceous perennial plant, meaning that it will continue to bloom season after season. This is due to the fact that its root system consists of a bulb that will remain alive even during the winter months, and the plant will flower again the following spring.

Flowers usually bloom in early June, and will remain in bloom for several weeks after – usually from early spring to late spring. This leaves for a moderate window of opportunity. If pollinated, right before they fall away, they will release small and round seed capsules that are filled with small black seeds.

Where does Blue Eyed Grass Grow?

Blue eyed grass is native to all of North America and some parts of South America. They can grow in USDA zones 4 through 9.

These plants can be found growing in the wild in prairies, parklands, open moist meadows, open forests, damp fields, and along shorelines.

Pale purple flowers of the blue eyed grass plant growing in dry conditions in a field

What are the Growing Conditions of Blue Eyed Grass?

Soil

Blue eyed grass can tolerate any level of acidity in its soil, and the soil can be relatively low in nutrients. The many requirements for soil are that it is well-drained, and never becomes completely dry or completely waterlogged. Sandy soil is usually a good option for this plant!

Mulch

When planting blue eyed grass on your property as ornamental grass, know that a little mulch goes a long way! Mulch provides organic material in low-nutrient soil and helps protect the growing plant against freezing temperatures.

Sun Exposure

It is best to plant blue eyed grass is an area that receives partial shade. Though this plant can tolerate existing in full sun, it will not bloom as readily or experience as much height.

Looking down at a patch of blue eyed grass with purple flowers in full bloom — loo

Water Level

The blue eyed grass plant tends to perform just fine with moderate levels of water, and needn’t be watered if it is a rainy season. Just ensure that the soil never completely dries out.

Temperature

Blue eyed grass grows all over North America in many different climates and temperatures. It can tolerate both very high heat and very low cold as well.

Fertilizer

These plants have adapted to exist in poor soil that is low in nutrients, and therefore they needn’t be given much fertilizer, if at all.

Fish eye lens shot of very pale blue blue eyed grass flower with blurry green background

Pruning

If you’re looking to keep your blue eyed grass nice and healthy, it may be a good idea to prune it. Do this by leaving the leaves intact until the blooms fall away in the late summer. This allows for the plant to gather energy to store in its rhizomes underground for the following season’s bloom. Once the leaves die, cut them back to above the crown.

To do this, cut away rhizomes from the main plant and plant them as individuals specimens away from the main plant. Each clump will become larger each year due to seed droppings.

Intolerances

Blue eyed grass is very resilient and doesn’t have many serious intolerances. They simply will not perform well if they experience full sun, drought, or flood – but this is quite regular for most plant species.

How is Blue Eyed Grass Used?

Incorporating blue eyed grass to your property is a wonderful and easy way to introduce a native and wild looking plant to your cottage garden or city planters.

They can be used in a rock garden, as border plants, they make for a great container plant, and they create the essence of a wildflower meadow.

Not only that, they are a very important source of nectar for pollinators like native bees, moths, and butterflies, and they help feed wild birds all year long as well. They turn any wild space into a woodland garden.

Bright and sunny patch of healthy green blue eyed grasses with beautiful purple flowers in bloom

FAQs

Is blue eyed grass invasive?

Because blue eyed grasses are native plants to North America, they cannot be considered as an invasive species. An invasive species is a plant or animal that is brought to a foreign land, and the local ecosystem is unable to harmonize with the new species.

That being said, some may consider blue eyed grass as having “invasive roots” because they are so dense, and spread further and further year after year. However, they are relatively easy to remove, and therefore still cannot be considered as invasive roots.

Is blue eyed grass deer resistant?

Blue eyed grasses are very deer resistant, and help as companion plants to help ward deer away from plants that are less deer resistant than they.

Is blue eyed grass a perennial?

Blue eyed grass is a perennial plant, meaning that it will continue to bloom year after year, whereas annuals will experience their bloom, seed, and death all within the year.

How should you transplant blue eyed grass?

Though blue eyed grass doesn’t necessarily need to pruned, it is beneficial for the plant for its roots to be separated. Plants that over developed tend to experience root rot, and their root system becomes too dense.

To do this, cut away rhizomes from the main plant and plant them as individuals specimens away from the main plant. Each clump will become larger each year due to seed droppings.

How should you prune blue eyed grass?

When does blue eyed grass bloom?

Blue eyed grass will usually bloom in the early spring or during the month of June, and will remain in bloom for a few weeks.

When should you plant blue eyed grass seeds?

It is best to attempt to mimic the natural reproductive pattern of a blue eyed grass, and to plant the seeds in the fall which will allow for the seed capsule to disintegrate throughout the winter, where then the foliage can sprout in the spring.

Does blue eyed grass spread?

Blue eyed grass is a plant the spreads quite readily. Its root system that consists of rhizomes is very resilient, and will continue to spread outwards year after year.

What hardiness zone does blue eyed grass exist in?

Blue eyed grass is native to all of North America and some parts of South America. They can grow in USDA zones 4 through 9.
These plants can be found growing in the wild in prairies, parklands, open moist meadows, open forests, damp fields, and along shorelines.

Do blue eyed grasses need mulch?

When planting blue eyed grass on your property as an ornamental grass, know that a little mulch goes a long way! Mulch provides organic material in low nutrient soil, and helps protect the growing plant against freezing temperatures.

Is blue eyed grass a true grass?

Blue eyed grass is not a true grass, but is instead a member of the iris family. This plant is a monocot, meaning that each individual seed contains its own embryonic leaf. It is called a grass because of its flowering stem that is a very similar shape and size to a blade of grass, when it is actually the entire stem and foliage of the plant.