Iris hoogiana (aril iris) — Clump-forming, upright

Overview

Iris hoogiana 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 hoogiana 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. It is native to Tadzhikistan and Uzbekistan.

About

Iris hoogiana is a clump-forming, upright perennial aril iris with sword-shaped foliage and a fragrant flowering season from May to July. Leaves are often glaucous and can be either deciduous or persistent. It prefers a sunny, south- or west-facing site with sharply drained soil. Take care when handling, as the plant is harmful if eaten.

Wikipedia contributors, CC BY-SA 4.0 — Iris hoogiana

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 hoogiana is an aril iris native to Tadzhikistan and Uzbekistan, grown for its spring–early summer flowers and distinct, often glaucous, sword-shaped leaves. Flowering occurs from May to July and the blooms carry a noticeable fragrance. Plants form upright clumps and suit gardens that can replicate a sunny, well-drained mountain edge. Plant into loam, chalk or sand-based soils with a neutral to slightly alkaline pH; bearded kinds prefer especially sharp drainage. Position in full sun where possible, although some specimens will tolerate light afternoon shade. A south- or west-facing slope or border gives warmth and drainage; the species will tolerate exposed or sheltered sites provided soils do not remain waterlogged. Classified H5–H7, Iris hoogiana is hardy in the UK from hardy to fully hardy. Use it where spring fragrance and vertical foliage are useful: sunny mixed borders, gravel beds or sunny banks. Wear gloves and take care when planting, dividing or dead-heading, as the plant is harmful if eaten and contact precautions are advised. Expect the chief interest to be concentrated in the May–July flowering window, when scent and form are at their best.

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 hoogiana size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright
Foliage: Deciduous or evergreen; sword-shaped to grassy, often glaucous
Native to: Tadzhikistan, Uzbekistan
Fragrance: Flower
Toxicity: Harmful if eaten. Wear gloves and other protective equipment when handling. Pets: Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants

Care notes

Pruning and caring for Iris hoogiana

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 hoogiana?

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 hoogiana?

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

What soil does Iris hoogiana need?

Iris hoogiana 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 hoogiana?

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 hoogiana hardy in the UK?

Iris hoogiana 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 hoogiana?

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.

Is Iris hoogiana toxic?

Harmful if eaten. Wear gloves and other protective equipment when handling. Pets: Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants.

More in the Iris genus

Browse all Iris →