Blue

Blue-Eyed Grass 'Devon Skies' (Sisyrinchium 'Devon Skies') is a tidy little clumper for the front of a bed, reaching only 25cm tall and 25cm wide. It is an iris relative rather than a true grass, and fine upright fans of foliage carry pale blue starry flowers over a long season. Evergreen, frost hardy and happy in damp ground, it handles edging jobs that defeat most small perennials.

Why you'll love it

• Flowers for months, not weeks. Pale blue stars open in flushes from spring through summer, each lasting a day and quickly replaced.
• Small enough for any garden. At 25cm by 25cm it edges a path or fills a rockery pocket without outgrowing it.
• It copes with wet ground. It tolerates wet feet, so a damp border or a pond edge suits it.
• Very little upkeep. A shear over after flowering and a divide every few years is the whole job.
• Bees find it quickly. The open flowers are easy nectar for bees and butterflies.

Where it works best

Borders and edging. Plant 25cm apart for a neat border. The clumps meet by the end of the first season and read as a continuous ribbon.

Mass planting and rockeries. The same spacing across a bed gives a fine textured carpet, and it slots into gravel and rock pockets where soil is shallow.

Pots and small gardens. Three plants fill a 300mm pot, and a courtyard bed can carry a run of them under taller shrubs.

Growing blue-eyed grass in Australia

Position and climate. Full sun gives the most flowers, though partial shade helps in hot inland gardens. This is a plant for cool temperate, warm temperate and Mediterranean climates. Humid subtropical summers are its weak point, where crowns rot in still air.

Soil. Any reasonable garden soil that does not dry out completely. It accepts damp ground and short spells of waterlogging, but not hard compacted clay. Compost through the bed at planting is enough.

Water and feed. Keep it damp through the first summer, then water weekly in dry spells. A light dressing of complete fertiliser in early spring covers the whole year.

Pruning. Shear the spent flower stems off after each flush to bring on the next. Divide clumps every three to four years so the centres do not go bare.

What to expect when it arrives

It comes as tube stock and in 140mm pots in packs of ten. Tubes are the value choice for a long border and fill out within a season. The 140mm plants arrive as established clumps, and a pack of ten covers roughly 2.5m of edging.

Strappy plants like this travel well, though the foliage often looks creased on arrival and straightens within a fortnight. Delivered Australia wide, delivery from $29.95. Every plant carries our 30 day healthy plant guarantee.

Plant care guides and related reading

• Ideas for the front of the bed in our guide to choosing the right edging plants.
• Browse the wider grasses and strappy leaf range.
• Find companions in rockery plants.
• Add more nectar with bee and butterfly plants.

Common questions

How far apart should I plant it?

Space plants 25cm apart for a border or mass planting. That is close enough for the clumps to merge in one season, and far enough that air moves between them.

Is it actually a grass?

No. It belongs to the iris family and only looks grassy, which is why it flowers so freely. The foliage stays evergreen rather than browning off in winter.

Will it spread through the garden?

It clumps rather than runs, so it stays where you put it. Seedlings can appear in damp open ground, though they are shallow rooted and easy to pull if you do not want them.

Does it need dividing?

Every three to four years. Lift the clump in early spring, split it into fist sized pieces and replant, which keeps flowering heavy and the centre full.