Iris korolkowi 'Violacea' — Clump-forming, upright

Overview

Iris korolkowi 'Violacea' is a clump-forming, upright perennial in the genus Iris, part of the Iridaceae family, with deciduous or evergreen; sword-shaped to grassy, often glaucous foliage. Iris korolkowi 'Violacea' grows best in full sun; some tolerate partial shade, and tolerates loam and chalk or sand; sharply drained for bearded kinds soils and neutral to slightly alkaline pH. Its UK hardiness is rated H5–H7. Suggested uses include borders, rock gardens, alpine gardens and and containers.. It is native to Central Asia and particularly Kazakhstan and surrounding regions..

About

Iris korolkowi 'Violacea' is a clump-forming, upright perennial iris from Central Asia, notable for its sword-shaped, often glaucous leaves. It flowers in the UK from May to July. Plant in full sun or light afternoon shade on neutral to slightly alkaline, sharply drained soils for best results.

About the genus

Iris takes its name from the Greek goddess of the rainbow, and for once the naming feels entirely earned. I can't think of another genus that covers so much ground — inky purples, burnt apricots, clean whites, blues that seem lit from inside — or so many situations. There are bearded irises that want their rhizomes baked in full sun, Siberian types happy in ordinary border soil, and species that will sit contentedly at the edge of a pond. What they share is the flower: three petals standing up, three falling away, built with a kind of architectural confidence most plants never attempt. Even out of bloom the foliage earns its place — those upright fans of blue-green leaves hold a border together for months. I grow them for the fortnight in May and June when nothing else in the garden can compete, and I've made my peace with that. Some plants are for the long haul. An iris is an event.

Written by Henry

In the garden

Iris korolkowi 'Violacea' belongs to the Iridaceae and is native to Central Asia, particularly Kazakhstan and surrounding regions. As a clump-forming, upright perennial it produces sword-shaped to grassy foliage that is often glaucous and may be deciduous or retain leaves through milder winters. Expect flowering in the UK from May to July. Choose a south- or west-facing spot in full sun; some plants will tolerate partial shade. It prefers neutral to slightly alkaline soils and suits loam, chalk or sand soils provided they are well drained; note that bearded irises in general do best in sharply drained positions. Soil moisture should be well drained rather than persistently wet, although moisture-retentive conditions are recommended for Siberian and Japanese types rather than bearded forms. Exposure can be either exposed or sheltered, and the plant copes across a wide range of climates (H5–H7, meaning hardy to fully hardy in the UK; USDA zones 3–9). Use Iris korolkowi 'Violacea' in borders, rock gardens, alpine pockets and containers where its neat upright clumps and glaucous leaves can be shown off; a south- or west-facing rockery suits it especially well. Flowering from May to July places its blooms at the main late spring to early summer display period for hardy irises in the garden.

Growing conditions

Best soil and position for Iris

Sunlight: Full sun; some tolerate partial shade
Soil type: Loam, chalk or sand; sharply drained for bearded kinds
Soil pH: Neutral to slightly alkaline
Soil moisture: Well drained; Siberian and Japanese kinds need moisture-retentive soil
Aspect: South or west facing
Exposure: Exposed or sheltered
UK hardiness: H5–H7

Plant details

Iris korolkowi 'Violacea' size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright
Foliage: Deciduous or evergreen; sword-shaped to grassy, often glaucous
Suggested uses: Borders, rock gardens, alpine gardens, and containers.
Native to: Central Asia, particularly Kazakhstan and surrounding regions.

Care notes

Pruning and caring for Iris korolkowi 'Violacea'

Cultivation: Plant bearded irises with the top of the rhizome exposed so it can bake in summer sun; beardless kinds sit just below the surface in richer, damper ground. Feed with a low-nitrogen fertiliser after flowering and keep the rhizomes clear of mulch and encroaching neighbours.
Pruning: Remove spent flower stems at the base. Trim the outer leaves back by about half in late autumn to reduce overwintering fungal spores, leaving the central fan intact.
Propagation: Divide rhizomes six to eight weeks after flowering, discarding the old woody centre and replanting vigorous outer sections. Species come from seed, but named cultivars will not come true.
Pest resistance: Generally trouble-free, though iris sawfly and slugs damage foliage and thrips can disfigure buds.
Disease resistance: Prone to leaf spot, and to rhizome rot wherever drainage is poor or planting too deep.

Frequently asked questions

How do I grow Iris korolkowi 'Violacea'?

Plant bearded irises with the top of the rhizome exposed so it can bake in summer sun; beardless kinds sit just below the surface in richer, damper ground. Feed with a low-nitrogen fertiliser after flowering and keep the rhizomes clear of mulch and encroaching neighbours.

Where is the best place to plant Iris korolkowi 'Violacea'?

Iris korolkowi 'Violacea' prefers full sun; some tolerate partial shade. It suits exposed or sheltered positions.

What soil does Iris korolkowi 'Violacea' need?

Iris korolkowi 'Violacea' grows best in loam and chalk or sand; sharply drained for bearded kinds soil. It prefers neutral to slightly alkaline soil. Aim for soil that stays well drained; siberian and japanese kinds need moisture-retentive soil.

How do I prune Iris korolkowi 'Violacea'?

Remove spent flower stems at the base. Trim the outer leaves back by about half in late autumn to reduce overwintering fungal spores, leaving the central fan intact.

Is Iris korolkowi 'Violacea' hardy in the UK?

Iris korolkowi 'Violacea' has an RHS hardiness rating of H5, meaning it is hardy in most of the UK, tolerating -15 to -10°C.

How do I propagate Iris korolkowi 'Violacea'?

Divide rhizomes six to eight weeks after flowering, discarding the old woody centre and replanting vigorous outer sections. Species come from seed, but named cultivars will not come true.

More in the Iris genus

Browse all Iris →