Sisyrinchium nashii ‘Suwannee’ (Nash’s Blue-eyed Grass)

Sisyrinchium nashii ‘Suwannee’ – A Complete Guide to Suwannee Blue-Eyed Grass

Sisyrinchium nashii ‘Suwannee’, commonly known as Suwannee Blue-Eyed Grass or Nash’s Blue-Eyed Grass ‘Suwannee’, is a compact native perennial with soft blue, star-shaped flowers, golden centers, and neat iris-like foliage. Despite its common name, blue-eyed grass is not a true grass. It belongs to the iris family, which explains its narrow sword-shaped leaves, flattened flower stems, and bright little blooms.

Small but memorable, ‘Suwannee’ brings a low haze of blue to paths, rock gardens, meadow plantings, sunny borders, rain garden edges, and pollinator gardens. It is refined enough for designed landscapes yet natural enough for native plantings, offering spring sparkle, fine texture, and easygoing performance in a compact package.

Quick Facts – Sisyrinchium nashii ‘Suwannee’

Compact, clump-forming native perennial with iris-like foliage and soft blue flowers.
Use: Ideal for edging, native gardens, meadow plantings, rock gardens, pollinator borders, rain garden edges, and low-maintenance landscapes.
Highlight: A tidy, floriferous blue-eyed grass selection with strong spring color.
Note: Sometimes seen under older trade references linked to Sisyrinchium angustifolium, but best treated as Sisyrinchium nashii ‘Suwannee’.

Botanical Name	Sisyrinchium nashii ‘Suwannee’
Family	Iridaceae – iris family
Common Names	Suwannee Blue-Eyed Grass, Nash’s Blue-Eyed Grass ‘Suwannee’
Plant Type	Compact herbaceous to semi-evergreen perennial; tufted and rhizomatous
Hardiness	Usually USDA Zones 6 to 9
Size	About 8 to 12 in. tall and 12 to 18 in. wide
Light	Full sun to light shade
Soil	Average to moist, well-drained soil; tolerates rocky or slightly alkaline sites
Bloom Time	Late spring to early summer
Flower Color	Soft blue to sky blue with yellow centers
Wildlife	Attracts native bees, small bees, syrphid flies, and other pollinators
Deer and Rabbits	Generally resistant, but not deer-proof
Drought Tolerance	Tolerates short dry spells once established
Toxicity	Not widely reported as toxic, but best treated as ornamental

Care – Quick

• Planting: Plant in spring or fall with the crown level with the soil.
• Light: Full sun gives best bloom; light shade helps in hot climates.
• Water: Keep moist during establishment; avoid winter sogginess.
• Feeding: Use compost lightly; avoid high nitrogen.
• Pruning: Shear after bloom if plants look tired or seedlings are unwanted.

Works Best If

Plant in small drifts. Several plants together create a much stronger blue effect than one isolated clump.

Watch For

Deep mulch, dense shade, and wet winter soil can weaken the crown.

What Is Sisyrinchium nashii ‘Suwannee’?

Description

Sisyrinchium nashii ‘Suwannee’ is a compact selection of Nash’s blue-eyed grass, a North American native perennial with grassy-looking leaves and iris-family flowers. It forms low tufts of narrow foliage and produces soft blue blooms with golden centers. The flowers are small, but in groups they read as a bright blue mist above the foliage.

‘Suwannee’ is valued for being tidier and more garden-worthy than many blue-eyed grasses. It spreads gently by short rhizomes, forming compact clumps rather than a loose or messy colony. Use it where a planting needs spring color, fine texture, and a natural look without losing polish.

Origin and Naming

‘Suwannee’ is associated with the Suwannee River region of northern Florida and limestone-influenced habitats. This helps explain its tolerance of average, rocky, sandy, and slightly alkaline soils. It has appeared in commerce under older naming connected to Sisyrinchium angustifolium, but the better name for this selection is Sisyrinchium nashii ‘Suwannee’.

Growth Habit and Size

This is a low, clump-forming perennial, typically 8 to 12 inches tall and 12 to 18 inches wide. The foliage is upright, narrow, and fresh green, giving the plant value even after flowering. Its small scale makes it ideal for path edges, meadow pockets, rock gardens, troughs, and the front of mixed borders.

Flowers and Bloom Season

Bloom usually occurs in late spring to early summer, often May to June. The soft blue flowers open best in bright light and may close in dull weather or later in the day. Because the flowers are petite, place ‘Suwannee’ where people pass nearby, such as along a walkway, patio, stone edge, or low border.

Hardiness and Climate

‘Suwannee’ is usually recommended for USDA Zones 6 to 9. It grows best in bright light with good drainage and some moisture during active spring growth. In cooler climates, full sun is ideal. In hotter regions, light afternoon shade can keep foliage fresher and reduce stress.

Deer and Rabbits

‘Suwannee’ is best described as generally deer-resistant and somewhat unpalatable, but not deer-proof. Nursery sources often list it as deer-resistant or note that deer and rabbits usually leave it alone. Browsing can still occur where deer pressure is high, especially on young transplants.

Drought Tolerance

Once established, Sisyrinchium nashii ‘Suwannee’ tolerates short dry spells and leaner conditions. It is useful in mixed native plantings where soil moisture changes through the season. However, drought tolerant does not mean drought loving. For the best bloom, provide even spring moisture while buds and flowering stems are forming. In prolonged summer drought, foliage may brown, slow down, or look less lush, especially in full sun.

Toxicity

Sisyrinchium nashii ‘Suwannee’ is not commonly listed among major toxic garden plants and is not widely reported as poisonous to people, dogs, cats, or horses. Still, it should be treated as ornamental rather than edible. Avoid intentional ingestion and supervise pets that chew garden plants.

Invasiveness

‘Suwannee’ is not considered invasive in normal garden settings. It spreads gently by rhizomes and may produce seedlings, but it is usually easy to manage. Divide clumps in spring if they become too wide, and shear after bloom if you want to reduce seedlings.

How to Grow and Care for Sisyrinchium nashii ‘Suwannee’

Light

Full sun produces the heaviest flowering, especially in cooler climates. In hot regions, morning sun with light afternoon shade is often ideal. Avoid deep shade, where plants stretch, bloom lightly, and lose density.

Soil

‘Suwannee’ grows well in average to moist, well-drained soil. It tolerates loam, sand, rocky soil, and slightly alkaline conditions. Good drainage around the crown is essential, especially in winter. Avoid heavy wet mulch packed over the plant.

Watering

Water regularly during the first growing season. Once established, provide supplemental water only during prolonged dry spells, especially in full sun. Spring moisture is more important than summer moisture because it supports flowering.

Fertilization

This is not a heavy feeder. A light spring topdressing of compost is enough in most soils. Avoid high-nitrogen fertilizer, which can encourage soft growth and reduce the compact, floriferous habit.

Pruning

Shear lightly after flowering if foliage looks tired or if seedlings are unwanted. Do not cut hard into the crown. Remove old foliage in late winter or early spring before new growth begins.

Winter Care

Drainage is the best winter protection. Keep mulch light and away from the center of the clump. In containers, protect pots from repeated freeze-thaw cycles and avoid soggy potting mix.

Container Growing

‘Suwannee’ grows well in troughs, low bowls, and pollinator containers if drainage is excellent. Use a well-drained potting mix and keep plants evenly moist during active spring growth.

How to Propagate Sisyrinchium nashii ‘Suwannee’

Propagate ‘Suwannee’ by division in spring as new growth begins. Lift the clump carefully, separate rooted sections, and replant them at the same depth. Water well until growth resumes. Because this is a named selection, seed may not produce identical plants.

Common Pests, Diseases, and Problems

Sisyrinchium nashii ‘Suwannee’ is generally low-maintenance when grown in bright light and well-drained soil. Most problems are cultural rather than serious pest issues.

• Root and crown rot: Usually caused by wet soil or mulch over the crown.
• Poor flowering: Often caused by too much shade, crowding, or excess nitrogen.
• Leaf browning: May occur after bloom, during drought, or in intense heat.
• Slugs and snails: Occasionally nibble young foliage in damp gardens.
• Thinning clumps: Divide every few years if flowering declines.

Design Ideas and Companion Plants for Sisyrinchium nashii ‘Suwannee’

Design ‘Suwannee’ with companions that enjoy sun to light shade, average to moist well-drained soil, and a naturalistic style. Use it as the early blue thread in a layered native planting, then let taller summer and fall companions carry the display forward.

• For bold summer flowers: Pair with Echinacea purpurea, a tough native coneflower for sunny borders and pollinator gardens.
• For graceful movement: Add Chasmanthium latifolium, a native grass for sun to part shade and average to moist soil.
• For golden spring color: Use Oenothera fruticosa, a bright sundrops species for sunny, well-drained plantings.
• For smooth foliage and pink bloom: Plant with Phlox glaberrima, a native smooth phlox for moist, well-drained soil.
• For fragrant fall color: Finish with Solidago odora, a sweet goldenrod with yellow flowers and strong pollinator value.

Frequently Asked Questions

References

New Moon Nursery – Sisyrinchium nashii ‘Suwannee’: https://newmoonnursery.com/nursery-plants/sisyrinchium-angustifolium-suwannee/

Lady Bird Johnson Wildflower Center – Sisyrinchium nashii: https://www.wildflower.org/plants/result.php?id_plant=SINA

Updated: June 2026 – Reviewed by Gardenia Editors