Iris florentina (Cemetery Iris) — Clump-forming, upright

Overview

Iris florentina 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 florentina 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 graveyards, borders and rock gardens. It is native to Middle East and Northern Africa.

About

Iris florentina is a clump-forming, upright perennial in the iris family, prized for its sweetly scented white spring flowers. It bears sword-shaped, often glaucous leaves that may be deciduous or persist through mild winters. Flowers appear in the UK from May to July and are most effective on a south- or west-facing site. Plant in neutral to slightly alkaline, well-drained soil and allow full sun, or light afternoon shade where summers are hot.

Wikipedia contributors, CC BY-SA 4.0 — Iris florentina

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 florentina originates from the Middle East and northern Africa and has been grown in Europe for many centuries. As a member of Iridaceae it forms a clear, upright clump with sword-like, often glaucous leaves and produces sweetly scented white blooms between May and July. It is a perennial suited to temperate gardens and tolerates exposed or sheltered positions. For cultivation choose a sunny spot on neutral to slightly alkaline soil such as loam, chalk or sand; the plant prefers good drainage and will not thrive in permanently waterlogged ground. Some forms related to bearded irises favour sharply drained situations. Leave room for air to circulate around the clump and plant where the aspect is south or west facing to maximise flower display. In British hardiness terms it is winter-hardy across much of the country (H5–H7: hardy to fully hardy). Use Cemetery Iris where a white, scented spring display is wanted: set it beside memorials or paths, in mixed perennial borders, or tucked into a rock garden with alkaline stone. The scented blooms combine well with late-spring bulbs and can be sited close to seating to be enjoyed at close range.

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 florentina size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright
Foliage: Deciduous or evergreen; sword-shaped to grassy, often glaucous
Suggested uses: Graveyards, borders, rock gardens
Native to: Middle East, Northern Africa
Fragrance: Sweet, pleasant

Care notes

Pruning and caring for Iris florentina

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 florentina?

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 florentina?

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

What soil does Iris florentina need?

Iris florentina 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 florentina?

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 florentina hardy in the UK?

Iris florentina 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 florentina?

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 →