Species

Iris unguicularisAlgerian Iris

2 other cultivars

perennial

Algerian Iris 'Walter Butt'

Iris unguicularis 'Butt Not'

The Story

Plant Bio

Iris unguicularis, commonly known as Algerian iris, is a low-growing perennial with slender, grass-like foliage and bell-shaped, violet-purple flowers that bloom in late winter to early spring.

The cultivar 'Walter Butt' is prized for its large, fragrant, pale silvery-lilac flowers that appear from late fall to early spring.

Uses & Benefits:

Adds vibrant purple color to winter gardens, evergreen structure, fragrant flowers.

Low water needs, drought tolerant, minimal pruning required.

Provides nectar for early pollinators, evergreen foliage supports winter habitats.

SpeciesIris unguicularisAlgerian Iris

Essentials

At a Glance

Plant Type

Perennial

Height

8 inches

Width

12 inches

Light

Full Sun, Partial Sun

Zones

7, 8, 9, 10

Water

Low to moderate

Humidity

Average

Lifespan

Perennial

Native To

Mediterranean region

Toxicity

Toxic if ingested

Bloom period

Late winter

In flower about 1 month of the year

Planting

How to Grow

Tuck rhizomes 2 inches deep in well-draining soil
Water regularly during active growth period
Place in full sun for best flowering
Mulch lightly to retain moisture and suppress weeds
Divide every 3-4 years in early spring
Protect from extreme cold with mulch in colder zones

Pro Tip

Ensure excellent drainage to prevent root rot during winter.

Keep It Thriving

Care Guide

Do

Water during dry spells 🌱
Mulch to keep roots cool and moist
Deadhead spent flowers to encourage more bloom
Divide every 3-4 years for vigorous growth

Don't

Overwater in winter ❌
Plant in poorly drained soil ❌
Expose to excessive shade ❌
Neglect dividing and pruning ❌

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Divide
Pest Check
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Drought-tolerant borderEvergreen groundcoverFragrant rock garden accent

Companion Plants

Lavender Sedum ArtemisiaYarrow Salvia

Multiply

Propagation Methods

Good to Know

Common Questions

Algerian Iris 'Walter Butt' questions

What zones can Algerian Iris 'Walter Butt' grow in?

Algerian Iris 'Walter Butt' is hardy in USDA Zones 7–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Algerian Iris 'Walter Butt' deer resistant?

Yes — Algerian Iris 'Walter Butt' is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Algerian Iris 'Walter Butt' bloom?

Algerian Iris 'Walter Butt' typically blooms in late winter through late winter. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Algerian Iris 'Walter Butt' need full sun?

Algerian Iris 'Walter Butt' does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Algerian Iris 'Walter Butt' drought tolerant?

Yes — once established (usually after the first full season), Algerian Iris 'Walter Butt' handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.