Narrow-leaved blue-eyed grass
Sisyrinchium angustifolium · Iridaceae
📷 Hugowolf · CC BY 3.0
The gardener's calendar
Ideal time to plant narrow-leaved blue-eyed grass: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Foliage
- Evergreen, fine and linear
- Flowering
- May to July, blue or purple flowers
- Adult size
- Approximately 40 cm tall
- Growth
- Moderate
- Hardiness
- Good, cold-resistant
- Origin
- North America (Bermuda and coastal regions)
- Soil type
- Well-drained, tolerates sandy soils
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Plant above soil level with a small mound: keeping the collar dry prevents rot. Water moderately, except when flowering when it appreciates a bit more moisture.
The common mistake
Burying the rhizome too deep is the classic trap: it rots underground and you only notice it the following spring.
The pro's trick
Divide clumps every 4-5 years in autumn: this rejuvenates the plant and gives you plenty of free plants.
Care
Light
Sisyrinchium angustifolium appreciates a sunny location for generous and vigorous flowering. Place it in full sun for at least 6 hours a day. It also tolerates partial shade, but flower production will be reduced.
Watering
Water moderately, keeping the soil slightly moist during growth and flowering. Reduce watering in winter. Let the soil dry between waterings to avoid root rot. This plant enjoys conditions that are neither too dry nor too wet.
Soil
Prepare well-drained soil, ideally sandy or slightly gravelly. Enrich it with potting soil or compost when planting. Avoid heavy and compacted soils that promote water stagnation and rot.
Fertilizing
A balanced fertilizer application in spring is more than sufficient. You can apply a light fertilizer in early summer to support flowering. Avoid excess nitrogen, which would promote foliage at the expense of flowers.
Pruning and maintenance
Remove spent flowers to extend blooming. In late winter or early spring, cut back any dry or damaged foliage. The plant requires little formal pruning and naturally maintains a neat, compact form.
Diseases and pests
This plant is generally robust and not particularly susceptible to diseases. Be sure to avoid stagnant moisture, which could promote fungal rot. No specific pests particularly affect it if the environment is well-drained.
Did you know?
Sisyrinchium angustifolium originates from the humid coastal regions of Bermuda and North America, which explains its common name 'Bermudiana'. Despite having ephemeral flowers (each flower lasts only one day), the plant produces them generously over several weeks, creating a renewed display each morning. Its fine and elegant leaves, characteristic of the Iridaceae family, are reminiscent of miniature iris foliage.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- Early crocusCrocus tommasinianus
- Tiger irisIris domestica
- Fringed irisIris japonica
- Japanese irisIris ensata
- Snow CrocusCrocus chrysanthus
- Golden-eyed GrassSisyrinchium californicum
Tips generated and checked by Viridia — adapt them to your local climate.