A small family of attractive, iris-like plants, grown for their abundant clusters of summer flowers. A elegant but often shorted-lived border perennial that is surprisingly easy to grow.
Family: Iridaceae (iris)
Botanical Name: Sisyrinchium
Common Names: yellow-eyed grass, blue-eyed grass, golden-eyed grass
Foliage: Evergreen or semi-evergreen, narrow pointed strap-shaped leaves.
Flowers: Erect stems bearing clusters of six-petalled starry flowers. In shades of yellow, cream or blue (depending on variety).
Flowering Period: Spring to Autumn.
Soil: Well-drained, moderately fertile, humus rich soil (chalk, sand or loam). Alkaline or neutral pH.
Conditions: Full sun. Best in a south facing aspect. Can be planted in either an exposed or sheltered possition.
Habit: Clump forming, tufted.
Type: Annual or rhizomatous perennial.
Hardiness: Most varieties are hardy in the UK.
Robust and easy to grow. Ideal for raised beds or front/middle of the border.
Plant in autumn or spring.
Avoid waterlogged conditions and protect from winter wet.
Lift and divide every few years to encourage the best flowering. The grassy-like foliage can be damaged in severe winters but usually rejuvenates in spring.
Remove discoloured or damaged foliage and cut back faded flower stalks in the autumn.
Generally pest and disease free.
Sow seeds in spring under a coldframe. Some varieties self-seed in ideal conditions.
Alternatively, divide established clumps in September or March. Most species dislike root disturbance, so they will take a couple of years to recover.
A small number of good garden varieties are available in the UK, from tall border varieties to dwarf forms ideal for path edging or the rockery.
Sisyrinchium bermudiana (common blue-eyed grass) bears violet-blue starry flowers from May to June. Height to 1ft (30cm), spread 6in (15cm).
Sisyrinchium bellum (Blue-Eyed Grass) is a very low growing form, reaching around 4in (10cm) in height. Blue-green leaves with clusters of blue to violet flowers in summer.
Sisyrinchium californicum (golden-eyed grass) is a semi-evergreen perennial that produces beautiful, star shaped, yellow flowers. Height to 1ft (30cm), spread 6in (15cm).
Sisyrinchium californicum brachypus is a dwarf form, just 6in (15cm) tall. Bright yellow flowers from June to October.
Sisyrinchium idahoense (Idaho blue-eyed grass) bears blue flowers with narrower petals. Height to 6in (15cm).
Sisyrinchium striatum (pale yellow-eyed grass) is a popular robust, clump-forming perennial, with greyish-green foliage. Pale yellow flowers in summer-autumn. Height to 2ft (60cm), spread to 1ft (30cm) or more. Good cultivars include "Variegatum" with yellow flowers and green foliage striped pale yellow.