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Iris

Common Name(s):

Phonetic Spelling
EYE-riss
This plant has low severity poison characteristics.
See below
Description

The Iris is one of the most popular perennials and is available in a variety of colors with varying blooming times. The family Iridaceae is a very large one of perennial herbaceous herbs growing from a rhizome, corm, or bulb. There are Iris varieties native throughout the world that offers the possibility of use in a native or woodland garden. 

The native habitats of the Iris range from North America, Europe, Africa, and Asia. They grow in meadows, deserts, mountain ranges, hillsides, and along streams. 

In Greek mythology, Iris is the Goddess of the Rainbow. The genus name, Iris, is from the Greek word for "rainbow' and is aptly named because of the variety of flower colors available. The genus has about 300 species and thousands of cultivars.

Different varieties require light from full sun to full shade. Neutral to alkaline soils are required for some species. They grow in mounds or drifts in rich soils; some prefer wet or marshy areas and even standing water.  Some can be grown as houseplants. They propagate through root division or by seed. Some varieties require rhizomes to be at soil level, while others tolerate planting corms and bulbs deeper in the soil. Most iris require periodic division of the rhizomes.  After blooming is complete, allow the foliage to deteriorate and then remove the spent foliage. 

The leaves tend to be long, strap-like, and sword-shaped, overlapping at the base, and oriented in one plane.  The flowers may be a single to several blooms. They are carried at the top of a naked stem. The stem can be as short as 3 inches in dwarf varieties to as tall as 3 feet. The showy blooms are 6-parted with three often distinctly marked outer, spreading, or pendant "falls" and three inner, erect "standards". The variety of iris colors range from blues to violets to yellows to oranges to white to even black and are prized as cut flowers in the perennial garden. The seeds are carried in a fruit capsule, but the division of rhizome or root is the best propagation method and helps to prevent overcrowding. 

Iris is most effective when planted in small groups or in mass plantings. They may be used as border plantings, foundation plantings, near a patio, and along walkways, woodlands, and meadows. They are perfect for a cutting garden or cottage garden.

Seasons of Interest:

Bloom:  Spring or Summer depending on species or variety   Foliage:  Spring or Summer     Fruit:  Fall

Quick ID Hints:

  • green sword-like foliage, basal leaves are commonly fan-shaped, leaves are 2-ranked and often flat.
  • small to large, showy orchid-like flowers in a variety of colors
  • blooms have 3 upright petals known as standards, 3 downward-facing sepals called falls,
  • fruit is a brown capsule

Insects, Diseases, and Other Plant Problems:  Potential insect pests include aphids, caterpillars, beetles, snails, slugs, spider mites, thrips, and whiteflies. They are susceptible to diseases such as bacterial soft rot, botrytis blight or gray mold, leaf spots, root and crown rots, rust, and viruses. 

To learn more about individual species, see the boxes below.

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy, and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.

 

 

Profile Video:
See this plant in the following landscapes:
Poolside Garden Juniper Level Botanic Gardens: Sunken Pond Garden Juniper Level Botanic Gardens: Front Shade Garden Juniper Level Botanic Gardens: Sunken Pond Garden Shaded Patio Garden Full Sun Flower Garden Shaded Patio Garden Juniper Level Botanic Gardens: Part Sun-Part Shade Gardens Juniper Level Botanic Gardens: Front Shade Garden
Cultivars / Varieties:
I. brevicaulis, I. cristata, I. domestica, I. ensata, I. germanica, I. hexagona, I. hollandica, I. latifolia, I. louisiana 'Black Gamecock', I. reticulata, I. tectorum, I. versicolor, I. virginica, ‘Jellicle Cat’
Tags:
#purple#bulb#poisonous#small spaces#houseplant#white flowers#purple flowers#pink flowers#yellow flowers#corms#orange flowers#interiorscape#spring flowers#rabbit resistant#cpp#deer resistant#rhizomes#large flowers#naturalizes#border planting#cutting garden#black flowers#border front#walkway planting#spring flowering bulbs#HS302#problem for cats#problem for dogs#problem for horses#woodland garden#Buncombe County Sun and Shade Garden#container plant#landscape plant sleuths course
 
Cultivars / Varieties:
I. brevicaulis, I. cristata, I. domestica, I. ensata, I. germanica, I. hexagona, I. hollandica, I. latifolia, I. louisiana 'Black Gamecock', I. reticulata, I. tectorum, I. versicolor, I. virginica, ‘Jellicle Cat’
Tags:
#purple#bulb#poisonous#small spaces#houseplant#white flowers#purple flowers#pink flowers#yellow flowers#corms#orange flowers#interiorscape#spring flowers#rabbit resistant#cpp#deer resistant#rhizomes#large flowers#naturalizes#border planting#cutting garden#black flowers#border front#walkway planting#spring flowering bulbs#HS302#problem for cats#problem for dogs#problem for horses#woodland garden#Buncombe County Sun and Shade Garden#container plant#landscape plant sleuths course
  • Attributes:
    Genus:
    Iris
    Family:
    Iridaceae
    Life Cycle:
    Bulb
    Perennial
    Recommended Propagation Strategy:
    Division
    Country Or Region Of Origin:
    North temperate America, Europe, Asia
    Fire Risk Rating:
    low flammability
    Particularly Resistant To (Insects/Diseases/Other Problems):
    deer and rabbit resistant (in general)
    Dimensions:
    Height: 1 ft. 6 in. - 2 ft. 6 in.
    Width: 1 ft. 0 in. - 2 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Bulb
    Herbaceous Perennial
    Perennial
    Poisonous
    Woody Plant Leaf Characteristics:
    Deciduous
    Maintenance:
    Medium
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Soil pH:
    Alkaline (>8.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Available Space To Plant:
    Less than 12 inches
    12 inches-3 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Display/Harvest Time:
    Fall
    Fruit Type:
    Capsule
    Fruit Length:
    1-3 inches
    Fruit Width:
    < 1 inch
    Fruit Description:
    The fruits is a brown capsule and measures 2 inches long and 1 inch wide.
  • Flowers:
    Flower Color:
    Black
    Blue
    Cream/Tan
    Gold/Yellow
    Orange
    Pink
    Purple/Lavender
    Red/Burgundy
    White
    Flower Value To Gardener:
    Good Cut
    Long-lasting
    Showy
    Flower Bloom Time:
    Spring
    Summer
    Flower Petals:
    2-3 rays/petals
    Colored Sepals
    Flower Size:
    > 6 inches
    Flower Description:
    One to several flowers at the top of a naked stem in bracteate heads. Perianth tubular with 6-parted segments with three pendent "falls" that are narrowed basally into a shaft, are spreading to deflexed above, are bearded or with colored trichomes or crest, or are lacking these traits often with a basal medial color patch. Three inner, erect "standards", variously colored, clawed and reduced. Three stamens, three styles, petaloid, overarching falls.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Blue
    Green
    Variegated
    Deciduous Leaf Fall Color:
    Gold/Yellow
    Leaf Type:
    Sheath
    Simple
    Leaf Arrangement:
    Rosulate
    Leaf Shape:
    Lanceolate
    Linear
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    > 6 inches
    Leaf Width:
    1-3 inches
    Leaf Description:
    The leaves are green to bluish-green, and blades, swords, or fans of foliage. They have parallel leaf veins. Range in size from 6 inches to 2 feet and are arranged in clumps. Strap-like, overlapping at base, oriented in one plane. Leaves are 2-ranked, linear to ensiform, flat or tetragonal. Basal leaves are commonly in fans. Cauline leaves are sheathing or in an apical tuft.
  • Stem:
    Stem Color:
    Green
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Container
    Houseplants
    Meadow
    Naturalized Area
    Patio
    Small Space
    Walkways
    Woodland
    Landscape Theme:
    Cottage Garden
    Cutting Garden
    Design Feature:
    Accent
    Border
    Foundation Planting
    Mass Planting
    Small groups
    Resistance To Challenges:
    Deer
    Rabbits
    Problems:
    Contact Dermatitis
    Poisonous to Humans
    Problem for Cats
    Problem for Dogs
    Problem for Horses
  • Poisonous to Humans:
    Poison Severity:
    Low
    Poison Symptoms:
    CAUSES ONLY LOW TOXICITY IF EATEN. SKIN IRRITATION MINOR, OR LASTING ONLY FOR A FEW MINUTES. Nausea, salivation, vomiting, abdominal pain, lethargy, diarrhea, elevated temperature following ingestion; skin irritation upon contact with seeds, rootstock, or cell sap. Highest concentration in rhizomes
    Poison Toxic Principle:
    Pentacylic terpenoids (zeorin, missourin and missouriensin), Irisin, iridin, or irisine
    Causes Contact Dermatitis:
    Yes
    Poison Part:
    Roots
    Sap/Juice
    Seeds