HybridContainer OK

Iris Bearded Immortality

Iris germanica 'Immortality'

a close up of a purple and yellow flower

A breakthrough reblooming bearded iris that produces pristine white flowers in both late spring and again in fall, extending the iris season dramatically. The pure white standards and falls are accented with a bright yellow beard, creating a classic and elegant display. This reliable rebloomer has won numerous awards and is considered one of the best white iris varieties for consistent performance.

Sun

Full sun

☀️

Zones

5–9

USDA hardiness

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Height

18-30 inches

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Planting Timeline

Zone:

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Start Indoors

Transplant

Direct Sow

Start Indoors

Transplant

Direct Sow

Showing dates for Iris Bearded Immortality in USDA Zone 7

All Zone 7 flower →

Zone Map

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Iris Bearded Immortality · Zones 5–9

What grows well in Zone 7? →

Growing Details

Difficulty

Easy to moderate

Spacing18-24 inches

SoilWell-drained, neutral to slightly alkaline soil

pH6.5-7.5

WaterModerate water, drought tolerant once established

SeasonPerennial, blooms late spring and fall

FlavorN/A

ColorPure white with bright yellow beard

Size5-6 inch blooms

Zone-by-Zone Planting Calendar

Zone	Indoor Start	Transplant	Direct Sow	Harvest
Zone 3	April – May	June – July	June – August	—
Zone 4	March – April	June – June	June – July	—
Zone 5	March – April	May – June	May – July	—
Zone 6	March – April	May – June	May – July	—
Zone 7	February – March	April – May	April – June	—
Zone 8	February – March	April – May	April – June	—
Zone 9	January – February	March – April	March – May	—
Zone 10	January – January	February – March	February – April	—
Zone 1	May – June	July – August	July – September	—
Zone 2	April – May	June – July	June – August	—
Zone 11	January – January	January – February	January – March	—
Zone 12	January – January	January – February	January – March	—
Zone 13	January – January	January – February	January – March	—

Complete Growing Guide

Light: Full sun (6 or more hours of direct sunlight a day). Soil pH: Alkaline (>8.0), Neutral (6.0-8.0). Drainage: Good Drainage, Moist. Height: 1 ft. 6 in. - 2 ft. 6 in.. Spread: 1 ft. 0 in. - 2 ft. 0 in.. Spacing: Less than 12 inches, 12 inches-3 feet. Maintenance: Medium. Propagation: Division. Regions: Coastal, Mountains, Piedmont.

Harvesting

The fruits is a brown capsule and measures 2 inches long and 1 inch wide.

Color: Brown/Copper. Type: Capsule. Length: 1-3 inches. Width: < 1 inch.

Harvest time: Fall

Storage & Preservation

Fresh-cut iris stems last 5-7 days in arrangements when properly conditioned. Recut stems under running water and place in clean vases with fresh water plus flower food. Change water every 2-3 days and trim stems slightly each time. For preserving the flowers, iris petals can be dried using silica gel for craft projects—bury flowers completely in silica gel for 3-4 days until papery. Seeds can be stored in paper envelopes in a cool, dry location for 2-3 years, though germination rates decline over time. Rhizomes can be stored short-term (2-3 weeks) in a cool, dry, well-ventilated area if you need to delay planting after dividing.

History & Origin

Origin: North temperate America, Europe, Asia

Considerations

-Toxic (Roots, Sap/Juice, Seeds): Low severity
-Causes contact dermatitis

Companion Plants

Lavender, Allium, Catmint, and Salvia all work well alongside bearded iris because they share the same preferences — full sun, lean-to-moderate soil, good drainage — without crowding the rhizomes or shading them out. Alliums are worth a specific callout: their sulfur compounds are genuinely off-putting to aphids and thrips, both of which chew up iris foliage. Sedum and Ornamental Grasses fill the gaps between clumps without running aggressive roots into the zone where rhizomes need to breathe and catch sun.

Mint is a problem not because of chemistry but because of behavior — it spreads by underground runners fast enough to physically displace iris rhizomes within a single growing season, cutting off the airflow and direct sun they need to rebloom in fall. Black Walnut is a harder limit: it releases juglone from its roots and decomposing leaf litter, and Iris germanica is sensitive enough that even a partially shaded drip zone can cause dieback. Hostas round out the avoid list simply because they need the opposite conditions — consistent moisture and shade — and planting them near iris tends to mean one of them is always grown wrong.

Plant Together

Lavender

Repels pests like aphids and thrips, both prefer similar well-draining soil conditions

Allium

Natural pest deterrent against iris borers and aphids, blooms complement iris timing

Catmint

Deters aphids and ants, provides ground cover without competing for nutrients

Salvia

Attracts beneficial insects, similar sun and drainage requirements

Ornamental Grasses

Provides structural support and wind protection, complementary root systems

Sedum

Excellent drainage companion, helps prevent root rot in iris rhizomes

Peonies

Similar care requirements, sequential blooming extends garden interest

Daylilies

Complementary bloom times, both thrive in similar growing conditions

Keep Apart

Black Walnut

Produces juglone toxin that inhibits iris growth and can cause yellowing and death

Mint

Aggressive spreader that competes for space and nutrients, can overwhelm iris rhizomes

Hostas

Requires more moisture and shade, creates overly humid conditions promoting iris soft rot

Pests & Disease Resistance

Resistance

Good resistance to iris borer, moderate soft rot resistance

Common Pests

Iris borer, thrips, aphids, slugs

Diseases

Soft rot, leaf spot, crown rot in poorly drained soil

Troubleshooting Iris Bearded Immortality

What you'll see, why it happens, and what to do about it.

Leaves show ragged, water-soaked streaks in spring, then collapse from the center outward as the season progresses

Likely Causes

Iris borer (Macronoctua onusta) — moth larvae hatch in spring and tunnel down the leaf into the rhizome
Secondary soft rot (Erwinia carotovora) moving into the borer's entry wounds

What to Do

1.In early spring, before new growth hits 6 inches, squish any visible egg masses on old leaf debris and remove that debris entirely
2.If you find a mushy, foul-smelling rhizome, dig it up, cut out the rotted section with a clean knife, dust the cut surface with sulfur powder, and let it dry in the sun for a day before replanting
3.In fall, cut foliage down to about 6 inches and clear it away — this removes overwintering borer eggs

Rhizomes sitting in soggy soil fail to bloom and show soft, discolored patches at the base even without visible borer damage

Likely Causes

Crown rot or soft rot driven by poor drainage — Iris germanica rhizomes are extremely intolerant of standing water
Planting too deep, which traps moisture against the rhizome surface

What to Do

1.Dig the rhizomes, let them air-dry for 24–48 hours, then replant in a raised bed or amended bed with at least 12 inches of well-draining soil
2.Replant so the top of the rhizome sits at or just barely below the soil surface — NC State Extension specifically recommends keeping rhizomes partially exposed to sun
3.Work coarse sand or fine gravel into heavy clay before replanting; keeping pH between 6.5 and 7.0 also discourages rot pathogens

Frequently Asked Questions

How long does Iris Immortality take to bloom after planting?▼

Iris 'Immortality' typically blooms the first spring after planting if you plant healthy rhizomes in late summer (July-September). Spring-planted rhizomes may not bloom until the following year, as they need time to establish strong root systems. First-year blooms may be smaller, with full-sized flowers appearing in the second year.

Is Iris Immortality good for beginners?▼

Yes, 'Immortality' is excellent for beginners due to its reliable blooming, good pest resistance, and forgiving nature. The main requirement is well-drained soil—if you can provide that, this iris is quite easy to grow. Its reblooming habit also gives novice gardeners two chances per year to enjoy success.

Can you grow Iris Immortality in containers?▼

Iris 'Immortality' grows well in large containers (minimum 18 inches wide and deep) with excellent drainage holes. Use a well-draining potting mix and place containers where they'll receive morning sun. Container plants need more frequent division (every 2-3 years) and consistent watering during growing season, but less fall rebloom in hot climates.

When should I plant Iris Immortality rhizomes?▼

Plant 'Immortality' rhizomes in late July through early September for best results. This timing allows rhizomes to establish strong root systems before winter while avoiding hot summer stress. In very cold zones (3-4), plant by mid-August to ensure adequate establishment before hard freezes.

Why isn't my Iris Immortality reblooming in fall?▼

Fall rebloom requires adequate summer moisture, established clumps (2+ years old), and proper fertilization timing. Avoid high-nitrogen fertilizers after mid-summer, ensure consistent watering during hot weather, and provide full sun. Very hot summers or overcrowded clumps can also reduce fall blooming—divide every 3-4 years to maintain vigor.

How do you divide Iris Immortality?▼

Divide 'Immortality' 4-6 weeks after spring bloom ends (typically July). Lift entire clumps, wash off soil, and cut rhizomes into sections with healthy fans of leaves. Each division should have firm, pest-free rhizome pieces. Trim foliage to 6-inch fans and let cut surfaces dry in shade for several hours before replanting to prevent rot.