Iris 'Saint Teresa' (IB) — Clump-forming

Overview

Iris 'Saint Teresa' (IB) is a plant with a clump-forming habit in the genus Iris, part of the Iridaceae family, with sword-shaped foliage. Iris 'Saint Teresa' (IB) grows best in full sun, and tolerates loam soils and neutral pH. Its UK hardiness is rated H7. Suggested uses include borders, rock gardens and containers.

About

Iris 'Saint Teresa' is a clump-forming Iris in the Iridaceae with sword-shaped foliage and a defined flowering season from May to July. It favours a sunny, south-facing site with some shelter and well-drained loam at neutral pH. The plant is rated H7, fully hardy across the UK when given a protected aspect. It works equally well in formal borders, rock gardens and larger containers where drainage is reliable.

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 'Saint Teresa' is a clump-forming member of the Iridaceae grown for its seasonal display between May and July. It produces erect, sword-shaped leaves that form a neat fan; the flowering period is concentrated in late spring to mid-summer. No specific origin is stated here, but its culture follows standard iris practice for sun-loving clump-forming species. Plant into a well-drained loam at neutral pH in a south-facing spot where the exposure is sheltered from the coldest winds. Full sun is important to encourage flowering; avoid heavy, waterlogged soils. The plant’s H7 rating means it is fully hardy in the UK, though choosing a slightly sheltered aspect will protect flower stems and reduce the risk of winter soddening. Use Iris 'Saint Teresa' in mixed borders where its upright leaves provide structure, in gravel or rock gardens with free-draining soil, or in containers with a gritty loam mix provided they are placed in full sun. After the flowering period, cut back spent flower stems to the base to keep the clump tidy and help reduce the risk of crown rot in late summer.

Growing conditions

Best soil and position for Iris

Sunlight: Full sun
Soil type: Loam
Soil pH: Neutral
Soil moisture: Well-drained
Aspect: South-facing
Exposure: Sheltered
UK hardiness: H7

Plant details

Iris 'Saint Teresa' (IB) size, habit and characteristics

Habit: Clump-forming
Foliage: Sword-shaped
Suggested uses: Borders, rock gardens, containers

Care notes

Pruning and caring for Iris 'Saint Teresa' (IB)

Propagation: Division, seed
Pest resistance: Good
Disease resistance: Good

Frequently asked questions

Where is the best place to plant Iris 'Saint Teresa' (IB)?

Iris 'Saint Teresa' (IB) prefers full sun. It suits sheltered positions.

What soil does Iris 'Saint Teresa' (IB) need?

Iris 'Saint Teresa' (IB) grows best in loam soil. It prefers neutral soil. Aim for soil that stays well-drained.

Is Iris 'Saint Teresa' (IB) hardy in the UK?

Iris 'Saint Teresa' (IB) has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.

How do I propagate Iris 'Saint Teresa' (IB)?

Division, seed.

More in the Iris genus

Browse all Iris →