Blue-eyed grass (Sisyrinchium angustifolium SASSY GRASS)

Overview

Blue-eyed grass, scientifically known as Sisyrinchium angustifolium SASSY GRASS, offers surprising color from the Iris family, despite its common name suggesting otherwise. This clump-forming perennial is highly valued for its neat, grass-like foliage topped with charming, violet-blue flowers accented by a yellow eye during late spring and early summer. Sisyrinchium angustifolium SASSY GRASS provides excellent texture and low-level blooms for informal garden settings.

This variety is a compact selection, often maturing around 1.5 feet tall, making it perfect for softening border edges or naturalizing in woodland garden areas. While its appearance is delicate, it establishes into a vigorous clump that, under ideal conditions, will readily self-seed to expand your patches of Blue-eyed grass over time.

Gardeners appreciate Sisyrinchium angustifolium SASSY GRASS for its medium maintenance requirements and adaptability across USDA hardiness zones 4 through 9. It naturally inhabits moist, open areas, indicating a preference for consistent moisture paired with sharp drainage—a key consideration for successful cultivation.

Fast Facts

• Plant Family: Iridaceae
• Plant Type: Herbaceous perennial
• Hardiness Zones: USDA Zones 4-9
• Size at Maturity:
  • Height: 1-1.5 ft
  • Spread: 1-1.5 ft
• Bloom Time: May to June
• Bloom Description: Blue
• Sun Exposure: Full sun to part shade
• Water Needs: Medium
• Maintenance Level: Medium

How to Grow

The best time to establish Sisyrinchium angustifolium SASSY GRASS is when planting spring-blooming perennials. Choose a location receiving full sun to light part shade, ensuring the site features medium moisture and well-drained soil. Good drainage is non-negotiable, even though Blue-eyed grass prefers soils that do not completely dry out between waterings.

Watering should be consistent, supplying medium moisture throughout the growing season, especially during dry spells. While Blue-eyed grass does not typically demand fertilizer, ensure rich soil preparation beforehand. To manage its natural tendency to self-seed aggressively in perfect conditions, you can shear back the foliage immediately after the bloom period concludes.

Dividing established clumps every two to three years is recommended to maintain vigor and prevent overcrowding. This division process also provides opportunities to spread this beautiful Sisyrinchium angustifolium SASSY GRASS throughout your garden space. No specific winter preparation is usually required for established plants in zones 4-9.

Landscape Uses

Blue-eyed grass excels in informal, naturalized settings where its fine texture can blend seamlessly with other low-growing species. It is highly recommended for woodland gardens, native plant areas, and cottage gardens where it contributes subtle, consistent blue tones. Consider using it as a light, airy border front, softening the edge of a walkway, or interspersing it among rocks in a rock garden.

Its grass-like habit pairs beautifully with broader-leaved plants that contrast its fine texture, such as Hostas tucked into shadier spots or Sedums in sunnier, drier sections. The small stature of Sisyrinchium angustifolium SASSY GRASS also makes it an excellent, low-maintenance groundcover in select regions.

Standout Features

Flower Qualities

• Showy

Noteworthy Characteristics

Sisyrinchium angustifolium, commonly called blue-eyed grass, is noted for its violet-blue flowers and branched flowering stems. Though its foliage is grass-like, the blue-eyed grasses belong to the iris family not the grass family. It is native to Missouri where it occurs in damp open woods, slopes and along stream banks throughout much of the State. It is a clump-forming perennial that features a tuft of narrow grass-like leaves (to 3/16” wide) typically growing to 12” (less frequently to 20”) tall. Clusters of violet-blue flowers (to 1/2” across), each with 6 pointed tepals and a yellow eye, appear in spring on stalks growing from leaf-like bracts atop usually branched flowering stems which are distinctively flattened. Sisyrinchium campestre, also a Missouri native, features pale blue to white flowers atop unbranched flowering stems. S. Angustifolium includes plants formerly classified as S. Bermudianum.Genus name comes from the ancient Greek name for another plant.Specific epithet means narrow-leaved.SASSY GRASS is a compact, floriferous selection of blue-eyed grass that features small blue flowers held above tidy clumps of grass-like foliage from late spring to early summer. Mature clumps will reach up to 18” tall with a similar spread.

Tolerances

(No data provided for Tolerances)

Potential Problems

Fortunately, Sisyrinchium angustifolium SASSY GRASS tends to be very robust in cultivation. Gardeners usually report no serious insect or disease problems affecting this perennial. The primary challenge relates to cultural conditions, often arising from poor drainage, which can lead to root issues, or providing too much shade, which reduces flowering performance.

If you notice excessive, unwanted seeding, remember that shearing the foliage immediately following the May to June bloom period is the best cultural control. For vigorous clumps, division every few seasons prevents overcrowding and rejuvenates the plant’s flowering potential.

Frequently Asked Questions

What hardiness zones is Blue-eyed grass suitable for?

This herbaceous perennial is quite resilient, thriving in USDA Hardiness Zones 4 through 9, providing good coverage across a wide range of climates.

How large does Sisyrinchium angustifolium SASSY GRASS grow?

Mature clumps typically reach a height between 1 and 1.5 feet, with a similar spread of 1 to 1.5 feet, forming a tidy, dense mound of fine foliage.

When does Blue-eyed grass bloom?

The characteristic small blue flowers appear reliably from May into June, significantly brightening the late spring garden before the summer heat sets in.

What sun exposure does Sisyrinchium angustifolium SASSY GRASS need?

For the best display of flowers, ensure this plant receives full sun, although it tolerates light to partial shade quite well.

Conclusion

The compact form and vibrant blue flowers of Sisyrinchium angustifolium SASSY GRASS make it an indispensable choice for adding fine texture and reliable color to intermediate garden layers. As a long-lived member of the Iridaceae family, this Blue-eyed grass asks mostly for consistently moist, well-drained soil. Check your local hardiness zone compatibility now and plan to incorporate this attractive perennial during the next appropriate planting window.

Propagation Tips

Division is the easiest and most common method for propagating healthy stands of Sisyrinchium angustifolium SASSY GRASS. When clumps become overly crowded, typically every 2–3 years, carefully dig up the entire clump in early spring or early fall. Use a sharp spade or knife to divide the tough root mass into smaller sections, ensuring each new division has a healthy set of roots and new shoots attached. Replant these sections immediately at the same depth in well-amended soil.

While Sisyrinchium angustifolium SASSY GRASS readily self-seeds opportunistically, saving viable seed requires patience. If you choose to delay shearing the foliage until late summer, mature seed capsules will form. Harvest these capsules when dry and scatter the seeds onto prepared soil surfaces, treating them as you would other small perennial seeds—lightly covering them and keeping the area consistently moist.