Species

129 other cultivars

perennial

Supreme Sultan Iris

The Story

Plant Bio

Iris x germanica is a clump-forming, rhizomatous perennial characterized by rigid, sword-shaped, blue-green leaves arranged in fan-like clusters. The species produces erect, branched stems bearing complex flowers with three upright petals called standards and three drooping petals called falls.

'Supreme Sultan' is a bicolor cultivar distinguished by its exceptionally large flowers, which measure up to seven and a half inches across. The blooms feature ruffled, golden-ochre standards and deep mahogany-red falls accented by a bright yellow beard.

Uses & Benefits:

Produces massive, highly structured bicolor flowers that serve as a dramatic focal point in late spring borders.

Provides excellent, long-lasting cut flowers and exhibits high drought tolerance once established.

Attracts native bees and other large insect pollinators to the garden with its prominent yellow beards.

SpeciesIris x germanicaGerman Iris

Essentials

At a Glance

Plant Type

Perennial

Height

40"

Width

24"

Light

Full Sun, Partial Sun

Zones

4, 5, 6, 7, 8, 9

Water

Low

Humidity

Low

Lifespan

Perennial

Native To

Europe, Western Asia

Toxicity

Toxic if Ingested

Bloom period

Late spring – Early summer

In flower about 2 months of the year

Planting

How to Grow

Select a planting site in full sun with exceptionally sharp drainage, amending heavy clay soils with organic matter or constructing raised beds.
Dig a shallow hole and build a small mound of soil in the center, placing the rhizome on top so its upper surface sits at or slightly above the soil line.
Spread the roots downward over the sides of the mound, fill in the hole with soil, and firm it gently to anchor the plant.
Water thoroughly immediately after planting to settle the soil, then withhold water unless conditions are exceptionally dry.

Pro Tip

When planting, leave the top of the rhizome exposed to the sun and air; burying the rhizome in soil or covering it with mulch traps moisture and triggers bacterial soft rot.

Keep It Thriving

Care Guide

Do

Trim foliage back to six inches in late fall to remove overwintering iris borer eggs and fungal spores.
Divide crowded clumps every three to four years in mid-to-late summer to maintain vigor and flowering.
Apply a low-nitrogen, balanced fertilizer sparingly in early spring to support bloom development.

Don't

Do not cover the rhizomes with mulch, as this traps moisture and promotes rot.
Do not use high-nitrogen fertilizers, which stimulate soft, rot-prone vegetative growth.
Do not cut into the old, leafless woody center of the rhizome when dividing.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Divide
Fertilize
Prune
Winter Prep

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Mixed BordersCottage GardensCutting GardensGravel Gardens

Companion Plants

Salvia nemorosa Nepeta faassenii Paeonia lactiflora

Multiply

Propagation Methods

Good to Know

Common Questions

Supreme Sultan Iris questions

What zones can Supreme Sultan Iris grow in?

Supreme Sultan Iris is hardy in USDA Zones 4–9: in that range it survives winter in the ground. Warmer than Zone 9, winter isn't the problem: it prefers colder winters, and summer heat can shorten its life.

Is Supreme Sultan Iris deer resistant?

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

When does Supreme Sultan Iris bloom?

Supreme Sultan Iris typically blooms from late spring to early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Supreme Sultan Iris need full sun?

Supreme Sultan Iris does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Supreme Sultan Iris drought tolerant?

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