Iris is a genus of 260–300 species of flowering plants in the family Iridaceae. The diversity of the genus is centred in the north temperate zone, though some of its most handsome species are native to the Mediterranean and central Asian areas. It takes its name from the Greek word for a rainbow, which is also the name for the Greek goddess of the rainbow, Iris. Some authors state that the name refers to the wide variety of flower colors found among the many species. As well as being the scientific name, iris is also widely used as a common name for all Iris species, as well as some belonging to other closely related genera. A common name for some species is 'flags', while the plants of the subgenus Scorpiris are widely known as 'junos', particularly in horticulture. It is a popular garden flower. The iris flower is a common symbol found in kimono fabrics, as well as in paintings and the short Japanese poetry style known as haiku.
Irises are perennial plants, growing from creeping rhizomes (rhizomatous irises) or, in drier climates, from bulbs (bulbous irises). They have long, erect flowering stems which may be simple or branched, solid or hollow, and flattened or have a circular cross-section. The rhizomatous species usually have 3–10 basal sword-shaped leaves growing in dense clumps. The bulbous species have cylindrical, basal leaves. The flowers commonly possess three sepals, three petals, and three broad pollen-receptive stigma branches, under which the pollen-producing anthers are hidden. Of the six petal-like floral segments in irises, the more erect inner ones are called standards and the usually drooping outer ones are called falls. These flower parts are located above the ovary (inferior ovary), which consists of three carpels unified into a single pistil. Ovules within the ovary portion become seeds, and the ovary matures into dry capsule fruits.
Table of Contents
0.5 - 4 feet
4 - 24 inches
6.5 - 7.0
Growth Nutrition of Irises
Nitrogen, potash, and phosphorus are essential for Iris, but excessive nitrogen promotes lush growth that is more susceptible to rot diseases. If applied in concentrated form, do not allow the fertilizer to come in direct contact with foliage and roots, as the plant may be damaged or killed.
The best fertilizers for irises are high in potassium (K) and phosphorus (P) but low in nitrogen (N). NPK values such as 5-10-10 or 10-20-20 are optimal for iris plants.
Types of Iris
According to the American Iris Society (AIS), plants fall into three main groups: Bearded, Aril, and Beardless.
The highly popular Bearded category all derive from I. germanica, a species native to southern Europe and the Mediterranean. The showy, full-petaled flowers have a sweet, floral fragrance and are marked by a beard at the base of the lower petals (falls). The beard is a small mat of soft, short hairs that may be the same color as the petals or contrasting – a little soul patch for attracting pollinators.
These plants have thick, fleshy rhizomes that grow with the tops of these exposed to the sun and air. The Bearded category has six groups based on shared characteristics such as size and flowering time. The shortest plants flower first, followed by intermediates, and the tallest are the last to bloom. Some reblooming cultivars flower first in spring with a second flush from late summer into early fall.
Miniature Dwarf Bearded: Miniature Dwarf Bearded (MDB) types are adorable early spring bloomers that flower in late March to early May and measure up to eight inches tall. They look spectacular massed in beds, containers, naturalized drifts, and rockeries.
Standard Dwarf Bearded: Flowering immediately after the MDBs, typically in April and May, Standard Dwarf Bearded (SDB) varieties top out at eight to 16 inches tall. They are superb for spring borders or to create large cushions of color in beds, containers, and drifts.
Blueberry Tart: Pretty as pastry, I. germanica ‘Blueberry Tart’ is a reblooming SDB with a striking color combo of periwinkle blue standards with magenta bases, sandy falls, and bold, cobalt beards. It grows 10 to 14 inches and is a standout massed in beds, borders, containers, and foundations or in cottage, courtyard, and cutting gardens.
Intermediate Bearded: Intermediate Bearded IB) types are beautifully branched plants that grow 16 to 27 inches tall and overlap the flower times of the Standard Dwarf Bearded and Tall Bearded groups, blooming throughout May and June. They are striking when mass planted in island beds or as specimens in mixed perennial borders.
Border Bearded: The Border Bearded (BB) group are similar in size to Intermediate Beardeds, growing 16 to 27 inches tall, and they flower in May and June. Border Beardeds are gorgeous for beds, borders, foundations, and as cut flowers. They also make a good choice in areas prone to high winds thanks to their sturdy stems.
Miniature Tall Bearded: Miniature Tall Bearded (MTB) types reach 16 to 25 inches tall and flower in May and June. With elegant, branched stalks, flowers in this group are prized for floral arrangements and form beautiful clouds of color in beds, borders, and foundation plantings.
Tall Bearded: Tall and stately, with robust, branched stems and multiple buds, Tall Bearded (TB) irises grow 28 to 48 inches tall and flower in May and June. They are fantastic for cut flowers or massed in island beds, borders, foundations, and drifts.
The Aril group is comprised of species in the Oncocyclus and Regelia sections of the Iris genus that are native to semi-arid and desert regions of the near East. These are tall and flamboyant plants that may or may not have beards but are best known for their extravagant range of rich colors – often with large, dark “eyes” and dramatic streaks, swirls, or veining. Highly fussy about their location, Arils demand excellent drainage, full sun, and thrive in hot locations.
Aril species are difficult to grow in all but the driest and hottest regions. However, cross breeding with Bearded varieties has produced many attractive hybrid cultivars. Known as “arilbreds” they are suitable for growing in most regions and typically flower in May and June. Not as widely used in home gardens as the other two groups, arilbreds can be found at online bulb houses and plant specialty sites. Popular arilbreds include cultivars like ‘Kalifa’s Joy’ and ‘Refiner’s Fire.’ To improve drainage and heat retention, raised beds are often used for growing Arils and arilbreds.
Beardless varieties comprise a number of different species native to Asia, Europe, and North America. These types typically enjoy areas with a high water table, such as beside bogs, creeks, and marshes. The rhizome is smaller than that of Bearded varieties, and looks more like a large corm with long, fibrous roots below.
This adaptation means Beardless rhizomes can be buried under a thick mulch to retain moisture without the concern of rot – a problem for Bearded varieties. Also, they’re not as susceptible to root borers either.
Spurias: Also known as blue iris, Spurias (SPU) belong to the species I. spuria, and are native to Africa, Asia, and Europe. Among the tallest of the Beardless group, they easily reach three to five feet in height. The elegant flowers have slim standards and falls that give an airy, dragonfly profile and make stunning cut flowers. Plants form large, attractive clumps that rarely need dividing and flower in May and June, overlapping Tall Bearded and Japanese groups. They require consistent, moist soil conditions from October to flowering.
Siberian: Sophisticated and reliable, Siberians (SIB), I. sibirica and I. sanguinia, are midsized plants of two to four feet in height, native to central Europe and Asia. They feature stylish, fluted petals that flower throughout May and June, overlapping with the earlier Tall Bearded and later Japanese varieties. For the first year after planting, keep the soil evenly moist. Although drought tolerant, Siberians perform much better in conditions that are wet in winter and moist through spring until flowering is finished.
Painted Woman: A flamboyant Siberian, I. sibirica ‘Painted Woman’ has lightly fragrant and uniquely colorful flowers that bloom in late spring to early summer. The pearly, pale blue to light pink standards are offset by large, magenta falls with heavily veined golden signals and shoulders. Plants grow up to 28 inches and require moist soil to flourish. Splendid when massed by pools, rills, or water features.
Japanese: Japanese (JI) types are native to Japan, China, Korea, and Russia. They provide a tall, refined presence with captivating orchid-like blooms on abundantly branching stems. I. ensata plants grow four to five feet tall and are among the latest to flower, blooming from late June to August. They make an excellent choice beside ponds or streams and require plenty of moisture, with wet soil conditions from October to bloom time. Plant rhizomes two to three inches deep in a water-collecting depression, then fill the depression with mulch to retain moisture – never allow the roots to dry out.
Lion King: You’ll roar with delight when you see the impressive, fully double blooms of this tall, summer flowering Japanese cultivar. I. ensata ‘Lion King’ flowers in early to midsummer and displays eye-catching, two-tone flowers of white with deep, royal purple edging and small, yellow signals. Reaching a stately 36 to 48 inches, these showy plants require moist, well-draining soil and look spectacular massed around rills, ponds, and water gardens.
Louisiana: The Louisiana group (LA), I. ser. Hexagonae, is comprised of five species – I. brevicaulis, I. fulva, I. giganticaerulea, I. hexagona, and I. nelsonii – native to Arkansas, Florida, Louisiana, and Mississippi. These attractive species grow two to three feet tall and hybridize freely within the group, producing flower colors not found elsewhere. Flowering in April and May, this is another moisture-loving group that thrives in aquatic or rain gardens, beside ponds and streams, or low-lying, moisture-retentive areas. Plant rhizomes with the top slightly above the soil and ensure the soil remains moist to wet.
Black Gamecock: An excellent example of the Louisiana group, I. hexagona ‘Black Gamecock’ flowers in late spring to early summer and features velvety flowers of deep royal purple with a slim yellow signal. Plant grow up to 60 inches and make magnificent cut flowers. Also an excellent choice for massing around ponds, pools, or water gardens – moist soil is a must.
Pacific Coast Native: Native Iris species grow all along the west coast of North America, from southern California right up to Alaska and the Arctic. However, the Pacific Coast Native (PCN) group, formerly Californicae (CA), is comprised of 12 to 14 species that occur predominantly in northern California, Oregon, and southern Washington. PCNs include species such as the Douglas (I. douglasiana), Purdy’s (I. purdyi,), and tough-leaf (I. tenax) irises.
Agripinella (Iris ensata)
A real show-stopper, these flowers have ruffled, rose pink petals and white centers with bright yellow throats. They bloom in early- to mid-summer and have petals that can grow up to eight inches wide. They look great in groups and are easy to grow in almost every climate.
Alida (Dwarf Iris)
Growing only 4-6 inches high, these irises are colored medium blue and have white and butter yellow markings. They bloom in late winter to early spring, and they look best when planted in large groups and as borders.
Alpine Majesty (Iris ensata)
These flowers grow up to 40 inches in height and have double elegant petals in bright white with yellow throats. The winner of several international flower awards, the flower grows well as long as the soil has adequate moisture, and they look great when planted along streams or pools.
Apollo (Iris Hollandica)
With large, bold petals that are white and tinted light blue, the flower has yellow falls and buttercup splotches. Their leaves are gray and reed-like, and they make great cut flowers and borders.
Blue Magic (Iris Hollandica)
These flowers are deep purple and have bright yellow blotches on its falls. Best when grown in full sun and in medium moisture, the Blue Magic grows up to 26 inches tall and is deer and rabbit resistant.
Blue Moon (Iris sibirica)
With clump-forming, bright violet blue petals, deep purple veins, and pale yellow bases, they can grow up to three feet tall and two feet wide. They are low-maintenance plants that stay fresh-looking all season long and grow best in full sun or partial shade.
Blue Spritz (Iris ensata)
This flower has lavender blooms with dark purple veins and yellow throats, and they bloom in early- to mid-summer. They grow up to almost three feet in height and look great in Japanese gardens or water gardens.
Blueberry Fair (Iris sibirica)
These flowers have heavily ruffled petals that are rich blue with a small white area towards the base. The blue-green foliage looks exceptional all season long, and they grow up to 32 inches tall and two feet wide.
Butter and Sugar (Iris sibirica)
With white petals and bright yellow falls, they bloom in late spring to early summer and have won several international flower awards. They look great near ponds and streams, and they do well in soil that is slightly acidic and even very dry.
Caesar’s Brother (Iris sibirica)
The winner of several international flower awards, this plant consists of deep purple, velvet-like petals that bloom from late spring to early summer. They can grow two feet wide and up to 42 inches high, and they are a low-maintenance plant that looks great in borders and flower beds.
Carol Johnson (Iris ensata)
The Carol Johnson has single, plum-purple petals atop pale blue falls and yellow throats. There are no serious diseases associated with this type of Iris, and they look best in large groups. They are also easy to grow and resistant to deer.
Casablanca (Iris Hollandica)
The Casablanca has pure white flowers and yellow-gold markings on its falls. Their sturdy stalks are surrounded by sword-like leaves, and they bloom for several weeks in late spring or early summer. Because they grow to more than two feet in height, they look great in vases and as borders.
Coho (Iris ensata)
One of the most attractive pink Irises, this flower consists of elegant, rounded, pure pink petals with a delicate golden color at the base. The winner of several international flower awards, the Coho blooms in early- to mid-summer and provides a great vertical interest in a garden. It is also very easy to grow.
Contrast in Style (Iris sibirica)
Striking in appearance, these flowers have deep purple petals accented in white with bright yellow bases. Lighter lavender petals sit atop them, and they bloom in late spring or early summer. They prefer full sun or partial shade, and like other Irises, they should never be ingested because they can cause severe discomfort.
Eye-Catcher (Dwarf Iris)
The Eye-Catcher Iris is white with rich blue markings and bright yellow crests, and it has grass-like, gray-green leaves. It grows up to six inches tall and is both deer-resistant and tolerant to drought.
Fond Kiss (Iris sibirica)
This flower’s extravagant look includes ivory white petals flushed with light pink and grey-green foliage. The winner of several international flower awards, the Fond Kiss is drought-tolerant and prefers soil with adequate moisture. It also grows up to three feet in height and presents a very elegant look.
Frilled Enchantment (Iris ensata)
With a height of up to 42 inches, this flower has won several international flower awards and has large, ruffled petals that are white and trimmed in a beautiful shade of mauve purple. It also has beautiful, sword-like foliage that is a real eye-catcher, as well as a beautiful vertical look for your garden.
George (Dwarf Iris)
This plant has petals that are deep violet purple with bright yellow centers. It has won several international flower awards and causes discomfort when ingested. It also looks beautiful under trees and in front of borders, and it looks even better when planted in groups of at least 20 bulbs.
Gordon (Dwarf Iris)
The Gordon has light blue petals, deep velvet falls, and a blotch of golden orange and white near the center. It can multiply into other shades and colors, and it needs well-drained soil and full sun to partial shade to look its best.
Granny Jean (Iris sibirica)
A clump-forming perennial, this plant has mauve pink flowers with dark veins and a light center. It can grow up to 32 inches tall and looks great in beds and borders, not to mention near ponds or streams.
Harmony (Dwarf Iris)
With well-shaped petals in deep royal blue and a gold crest trimmed in white, these Irises look great in rock gardens, under trees, and in front of borders. They are deer-resistant and can tolerate drought, and they grow 4-5 inches high.
Katharine Hodgkin (Dwarf Iris)
The winner of several international flower awards, these flowers have pale blue petals with deep blue veins and a creamy yellow blotch at the center. They bloom in late winter to early spring, and they look great in both containers and rock gardens.
Lavender Bounty (Iris sibirica)
A low-maintenance perennial, the Lavender Bounty consists of ruffled, lavender pink flowers and white markings, and it blooms from late spring to early summer. It can grow up to two feet wide and is resistant to deer.
Magic Opal (Iris ensata)
With bright yellow throats and delicate mauve veins, this lilac pink flower grows up to three feet tall and does best in full sun or partial shade. As long as the moisture is adequate, it can grow almost anywhere, and it looks great alongside pools or streams.
Over in Gloryland (Iris sibirica)
These are dramatic in appearance because of their dark purple, ruffled petals that reach up to five inches in width. The petals have a light, white-yellow center and blue-green leaves that are fairly rigid. They grow up to three feet in height and look striking in any garden.
Perry’s Blue (Iris sibirica)
With sky blue petals that contain dark veins and white markings, this plant reaches up to three feet high and does best in full sun or partial shade. They are low-maintenance and look great near ponds and streams, not to mention in beds and borders.
Pink Frost (Iris ensata)
With ruffled lavender pink petals, white blotches, and a yellow throat, this type of Iris blooms in early- to mid-summer and does great in Japanese gardens and water gardens. It is easy to grow and can reach up to 30 inches high. It looks great in large groups because it creates a bouquet effect.
Pixie (Dwarf Iris)
The Pixie has dark blue-violet petals that grow almost three inches wide, and they have falls that contain white and gold markings. They are tolerant of drought, deer-resistant, and look great when planted with at least 20 other bulbs. They look perfect under trees, at the front of borders, and in containers.
Pleasant Earlybird (Iris ensata)
This flower has single pastel lavender blooms with a white halo and yellow throats. It has won several international flower awards and looks great alongside pools or streams. They even grow great in wet and acidic soil.
Professor Blaauw (Iris Hollandica)
These beautiful deep blue-purple flowers have bright yellow throats and grow up to four inches wide. They have won several international flower awards, and if you plant at least 20 bulbs together, they look extraordinary. They also look great in borders and beds.
Queen’s Tiara (Iris ensata)
The Queen’s Tiara consist of wide white petals that can grow as large as six inches across, with purple veins and yellow throats. It grows up to three feet high and its exquisite blooms show up in early- to mid-summer. Easy to grow, they also provide a beautiful vertical look for your garden.
Returning Tide (Iris ensata)
With large, five-inch-wide lavender petals, the flowers have a whitish tint and yellow throats. It has won honorable mention in at least one international flower competition, and it is deer-resistant, easy to grow, and perfect for water gardens or Japanese gardens.
Ruffled Velvet (Iris sibirica)
A broad, deep purple flower with purple falls and white-yellow bases, these flowers grow up to 30 inches tall and are striking because of their contrasting colors. They prefer adequate moisture and are resistant to deer.
Shirley Pope (Iris sibirica)
These flowers have dark, velvety, deep purple petals and white-purple-yellow bases. They have won several international flower awards, grow up to 32 inches high, and look great in borders and flower beds.
Silver Edge (Iris sibirica)
The Silver Edge has petals in sky blue with thin, silvery edges. Their centers are yellow and white, and they grow up to 30 inches high and 24 inches wide. They have won several international flower awards, and they bloom in late spring to early summer.
Sky Mirror (Iris sibirica)
With pale, sky blue petals with navy blue near the base, these flowers grow to almost three feet in height and have blade-shaped, fairly rigid leaves. Because it stays fresh-looking all season long, this flower is one of the most popular types of Irises.
Sky Wings (Iris sibirica)
This Iris has petals of sky blue with a delicate yellow center, and is stunning when planted in large groups. It has grass-like foliage and upright leaves that get up to three feet tall, and it does best in full sun or partial shade. It is also low-maintenance and great near ponds or streams.
Strawberry Fair (Iris sibirica)
These flowers have petals that are heavily ruffled and consist of colors such as lavender pink with magenta pink falls and white-blue edges. They grow up to 30 inches tall and up to two feet in width, and their striking looks have garnered several international flower awards.
Super Ego (Iris sibirica)
The winner of several international flower awards, these plants have pale blue flowers that are flushed in lighter blue, and they have sturdy narrow stalks. They can grow up to 30 inches tall and are tolerant to drought, not to mention deer-resistant. They look beautiful in beds and borders, and do best in medium to wet soils.
Variegata (Iris ensata)
The winner of several international flower awards, this flower has very small, purple petals with a reddish tint and a small yellow throat. Its silver-white foliage is extraordinary, and it blooms in mid- to late-summer. It also does best in full sun or partial shade, and it is a plant that is easy to grow.
White Swirl (Iris sibirica)
These clump-forming perennials have large white petals with delicate golden flushes at the base. They have won several international flower awards and do best in full sun or partial shade. They have beautiful blade-shaped leaves that catch anyone’s attention, not to mention they look spectacular when planted in large groups.
Irises will bloom best in full sun, meaning at least 6 to 8 hours of sunlight per day. They can tolerate as little as half a day of sun, but it’s not ideal. Without enough light, they won’t bloom well. Bearded irises must not be shaded out by other plants; many do best in a special bed on their own.
Provide well-draining, fertile, neutral to slightly acidic soil. Loosen soil to a depth of 12 to 15 inches, then mix in compost or aged manure. Good drainage is critical: Irises prefer “wet feet, but dry knees.” They will not tolerate wet soil in winter.
When to Plant Irises
Plant most irises in late summer to early fall, when nighttime temperatures remain between 40° and 50°F (4° and 10°C) or above. This gives them plenty of time to get established before the coming winter.
Tall bearded iris varieties are best planted closer to fall because they tend to go dormant in early to mid-summer.
If you receive bare rhizomes or irises in a container at some point earlier in the year, go ahead and plant them as soon as convenient. It’s better to get them in the ground rather than wait until the “ideal” time.
How to Plant Irises
Plant bare-root rhizomes (the thick stems) horizontally, with the top exposed and only the roots underground. In areas with particularly hot summers, set the rhizome just below the soil surface.
Dig a hole 10 inches in diameter and 4 inches deep. Make a ridge of soil down the middle and place the rhizome on the ridge, spreading the roots down both sides. Fill in the hole and firm it gently, leaving part of the rhizome and the foliage uncovered.
Plant singly or in groups of three, 1 to 2 feet apart, depending on the fully grown plant’s size.
Soak Siberian iris rhizomes in water overnight before planting, then set them 1 inch deep (2 inches, if the soil is sandy), 2 feet apart. Over a period of years, they will form clumps; divide when blooms get smaller and vigor declines.
Do not mulch around the rhizome as this may encourage rot.
Different species of irises require slightly different methods of and timing for planting. Bulbous irises, which includes Dutch, Spanish, and reticulata irises, are planted in the fall in full sun in well-draining soil.
To plant your bulbs, loosen the soil, then mix in compost and 1/4 cup of all-purpose granular fertilizer according to the directions on the bag. Situate the bulbs 4 to 5 in. deep, depending on the type of bulb. For bearded irises, position rhizomes horizontally in the soil, leaving the top of the rhizome partially exposed. For other varieties, position the crown of the plant 1/2 to 1 in. below the the soil line.
Once flowers are spent, deadhead the blooms. When the whole stalk of flowers is spent, cut the stalk to the ground to direct energy to the roots, instead of forming seed heads. Once the first heavy frost comes or your leaves yellow for the season, you can cut your iris foliage to the ground to prevent iris bores from overwintering in the leaves. However, do not be tempted to remove the foliage before then, as the greenery is still performing photosynthesis, providing the plant with energy necessary for next year’s blooms.
Once the foliage is trimmed back for the winter, be sure to cover the rhizomes with something to help protect them, such as sand or mulch. Remove this in the spring. Irises are a great choice for areas with wildlife as they are deer resistant. Common pests include iris borers.
Most iris varieties do best in full sun. Some varieties can tolerate partial shade, but too much shade will prevent them from flowering.
Rich, well-draining soil is best for iris plants. Though they like moist soil, too much water can be damaging. If you are worried about too much standing water, try planting your irises in raised beds, as this will allow for optimal water drainage. Japanese and Louisiana irises can tolerate moist soil and are excellent for areas near ponds. Siberian irises prefer acidic, moist soil.
Because the iris likes both moisture and well-draining soil, watering consistently and deeply is very important. Just be sure not to overwater, as too much water in the soil can cause problems such as root rot. Though they appreciate consistent water, most iris varieties are drought-resistant and won’t die quickly if they are deprived of water for a short time.
Temperature and Humidity
With its wide range of varieties and growing zones, the iris is a hardy plant that can tolerate fluctuations in temperature and humidity. As long as the soil is well-draining and they get plenty of water and sunshine, these flowers can thrive in a large variety of gardens. Siberian, Bearded, and Japanese irises typically are hardy in USDA zones 3-9; Iris reticulata and Dutch iris are hardy in zones 5-9; and Louisiana iris prefers zones 6-9.
Because irises prefer rich soil, compost makes a perfect amendment. Loosening the soil in the spring and adding a healthy layer of compost will help give your irises the nutrients they need to grow healthy and lush.
If you do not have compost, a well-balanced fertilizer for flowers works well. Just beware of too much nitrogen, which can lead to rot. Because some varieties bloom twice, once early in the season and once later in the season, these varieties will appreciate another dose of fertilizer before their second bloom.
Irises as Cut Flowers
Cut flowers for arrangements when they are just showing color.
Vase life is 3 to 7 days.
Irises spread underground through rhizomes or bulbs and will need to be divided every 3 to 5 years, creating the perfect opportunity to spread your irises to new landscaping areas. You will know when it is time to divide when you have fewer blooms or there are rhizomes popping out of the ground. Follow these basic steps to propagate iris plants:
Wait for 6 to 8 weeks after your irises have finished blooming. Then, with a garden fork or shovel, slowly work around each plant to loosen the rhizomes or bulbs.
Gently lift the iris out of the ground and shake out the dirt.
Once the dirt is removed you will be able to see the rhizomes or bulbs. You will find smaller rhizomes spreading from the larger mother rhizome. Some may come away naturally while others will need to be cut. Either way, divide these smaller rhizomes and toss any old, shriveled rhizomes.
Once you divide the rhizomes and remove any that are spent or diseased, simply plant the divided iris plants in a new location.
Pests and Diseases of Iris
Aphids are one of the most common plant pests and can affect irises and most other plants in your garden.
Beetles are another common pest, and many species love the taste of iris leaves and flowers.
Iris Borers are nasty pests that are the caterpillars of moths that overwinter in the foliage as eggs.
Thrips are tiny insects that can affect both the roots and foliage of a plant.
Bacterial leaf blight (Xanthomonas campestris) tends to spring up when your iris’s leaves get wet.
Botrytis rot (Botrytis convoluta) is a deadly fungal infection that can affect the entire plant but is concentrated in the roots of rhizomatous irises.
Crown rot (Corticium rolfsii) affects bulbous irises and affects the leaves.
Inkspot (Drechslera iridis) also affects bulbous irises and affects both the bulbs and leaves.
Leaf spot (Mycosphaerella macrospora) is a common fungal infection that tends to appear in overwatered plants or on leaves that have had water sitting on them.
Nematodes can often be beneficial, but some species, such as Ditylenchus destructor, are harmful to iris bulbs.
Soft rot (Erwinia carotovora) affects iris rhizomes that have been damaged and are often a consequence of iris borer damage.
Viral infections are incurable and often affect various plants, making it easy for the disease to spread through your garden.
Irises are affected by a range of viral diseases, including:
Bean yellow mosaic
Bearded iris mosaic
Beardless iris mosaic
Broad bean wilt
Iris mild mosaic
Iris severe mosaic
Narcissus latent virus
Rhizomes of the German iris (I. germanica) and sweet iris (I. pallida) are traded as orris root and are used in perfume and medicine, though more common in ancient times than today. Today Iris essential oil (absolute) from flowers are sometimes used in aromatherapy as sedative medicines. The dried rhizomes are also given whole to babies to help in teething. Gin brands such as Bombay Sapphire and Magellan Gin use orris root and sometimes iris flowers for flavor and color.
For orris root production, iris rhizomes are harvested, dried, and aged for up to 5 years. In this time, the fats and oils inside the roots undergo degradation and oxidation, which produces many fragrant compounds that are valuable in perfumery. The scent is said to be similar to violets. The aged rhizomes are steam-distilled which produces a thick oily compound, known in the perfume industry as "iris butter" or orris oil.
Iris rhizomes also contain notable amounts of terpenes, and organic acids such as ascorbic acid, myristic acid, tridecylenic acid and undecylenic acid. Iris rhizomes can be toxic. Larger blue flag (I. versicolor) and other species often grown in gardens and widely hybridized contain elevated amounts of the toxic glycoside iridin. These rhizomes can cause nausea, vomiting, diarrhea, and/or skin irritation, but poisonings are not normally fatal. Irises should only be used medicinally under professional guidance.
The juice is also sometimes used as a cosmetic and for the removal of freckles from the skin.
Iris flower can be used to make perfumes and body lotions.
Rubbing the extract of these flowers help to cure skin and hair problems like acne signs, split ends, irritated scalp and gently rub it in.