Butterfly Iris

Butterfly Iris (Dietes iridioides) is a clumping, grassy plant that grows to about 1m tall and 60cm wide and carries white, butterfly-like flowers on long stems through the warmer months. It takes full sun or part shade, drought and frost with equal calm, and asks for very little once it has settled in. It is the smaller cousin of fairy iris, with smaller, all white flowers.

Why you'll love it

• White flowers in succession. Six petalled white blooms appear in flushes from spring into autumn. Each lasts a day or two, but a mature clump keeps producing new ones.
• Hardy in drought and frost. Established clumps get by on rainfall in most climates and take frost in their stride.
• Sun or part shade. It grows in full sun to partly shaded positions and tolerates most soils, from clay to sand.
• Holds ground and smothers weeds. Planted densely it suits steep embankments and erosion control, and the clumps shade out most weeds.
• Low maintenance. After the first twelve weeks it needs little more than an annual feed and the occasional division.

Where it works best

Borders and edging. Plant 50cm apart in a single row for a continuous fan of foliage along paths, driveways and garden beds.

Slopes and erosion control. The same 50cm spacing, staggered, binds steep embankments and bare banks, and it also does well around waterways.

Rockeries, underplanting and pots. It slots between rocks and beneath trees and shrubs, and it suits a large pot at least 40cm wide.

Coastal and poolside gardens. It tolerates salt air, so it suits beachside and poolside plantings.

Growing Butterfly Iris in Australia

Position and climate. Full sun to part shade, with the heaviest flowering in sun and thinner flowering in deep shade. It is drought and frost hardy, so it suits subtropical, warm temperate, cool temperate, Mediterranean and semi arid gardens. A hard frost may mark the leaves, but the damage is cosmetic.

Soil. Most soils are fine. It prefers decent drainage but copes with clay, sand and the occasional wet spell. Set the top of the rhizome level with the surrounding soil, because planting too deep causes rot.

Water and feed. Mulch and water regularly until established, usually around 12 weeks, then leave it to the weather. Feed once a year with a slow release fertiliser. Too much nitrogen gives floppy leaves and fewer flowers.

Pruning. Do not cut off flower stems after flowering, because the same stems flower again for several seasons. Snap off only the green seed capsules. Every few years, lift and divide a congested clump, or cut the whole clump back to about 15cm in early spring.

What to expect when it arrives

We sell Butterfly Iris as tube stock, in 140mm pots in packs of 10 and in 200mm pots in packs of 6. A tube is a young plant in an 80mm deep tube that establishes quickly, and it is the value choice for borders and slopes. The potted packs give a fuller clump in the first season.

Plants are delivered Australia wide, with delivery from $29.95. Every plant is covered by our 30 day healthy plant guarantee.

Plant care guides and related reading

• Our Dietes care guide: pruning, dividing and watering
• More grasses and strappy leaf plants
• Plants for retaining walls and slopes
• Plants for mass planting

Common questions

Is it the same as fairy iris?

They are close relatives, but not the same plant. Butterfly Iris is the smaller one, with smaller all white flowers, which suits narrow beds, edging and pots.

Should I cut off the flower stems when they fade?

No. The same stems flower again for several seasons, so snap off only the green seed capsules and cut a stem out once it has turned brown and woody.

Is it an Australian native, and will it self seed?

It comes from Africa, not Australia, although it behaves like a tough native. It can self seed, so remove the seed capsules if you garden near bushland.