Iris 'Monspur' 'A. J. Balfour' — Clump-forming, upright

Overview

Iris 'Monspur' 'A. J. Balfour' 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 'Monspur' 'A. J. Balfour' 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 and cut flowers.

About

Iris 'Monspur' 'A. J. Balfour' is a clump-forming, upright perennial in the iris family that flowers from May to July. It carries sword-shaped to grassy leaves which are often glaucous in tone. Best grown in a sunny, south- or west-facing spot in neutral to slightly alkaline, well-drained soil.

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 'Monspur' 'A. J. Balfour' sits in the Iridaceae as a clump-forming, upright perennial and produces its season of interest from May to July. The foliage ranges from sword-shaped to grassy and often shows a glaucous bloom, giving the clump a cool, architectural base while the flowering season provides vertical accents in late spring to mid-summer. Place this iris in full sun where possible, although some tolerance of partial shade exists. Soils of loam, chalk or sand are appropriate; the species group prefers neutral to slightly alkaline conditions and good drainage—note that sharply drained sites are important for bearded types, while Siberian and Japanese irises require more moisture-retentive ground. Give a south- or west-facing aspect where the plant will receive the most warmth and light. Hardiness is H5–H7, equivalent to hardy through fully hardy, and the USDA range 3–9 shows suitability across cold to milder areas. Use Iris 'Monspur' 'A. J. Balfour' in mixed borders or rock gardens where its upright habit and seasonal flowers can be seen, and cut stems during May to July for indoor arrangements. Its combination of glaucous foliage and a concentrated flowering window makes it straightforward to site with other perennials that either flower earlier or later.

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 'Monspur' 'A. J. Balfour' 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, cut flowers

Care notes

Pruning and caring for Iris 'Monspur' 'A. J. Balfour'

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 'Monspur' 'A. J. Balfour'?

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 'Monspur' 'A. J. Balfour'?

Iris 'Monspur' 'A. J. Balfour' prefers full sun; some tolerate partial shade. It suits exposed or sheltered positions.

What soil does Iris 'Monspur' 'A. J. Balfour' need?

Iris 'Monspur' 'A. J. Balfour' 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 'Monspur' 'A. J. Balfour'?

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 'Monspur' 'A. J. Balfour' hardy in the UK?

Iris 'Monspur' 'A. J. Balfour' 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 'Monspur' 'A. J. Balfour'?

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 →