Plant Bearded Iris for a Fantastic Spring Display (2022)

Few flowers can boast the diversity and distribution of the Iris genus, which includes several distinct groups, each with unique cultural needs. Although all irises share sword-like leaves and flowers with six spreading or drooping lobes, there are groups that grow from creeping rhizomes while others grow from bulb structures; some iris groups are categorized as "bearded," others as "beardless," and still others as "crested." Japanese, Dutch, and Siberian iris are among those that fall into the beardless category. But the bearded iris (Iris germanica) is arguably the most popular and is among the easiest to grow. From nursery starts, the bearded iris is normally planted in the spring and will flower in its first year. If planted from bare roots, it can be planted in the fall or the spring; bare root plants may not flower robustly until their second year. These plants are toxic to dogs and cats.

Common NameBearded iris
Botanical NameIrisgermanica
FamilyIridaceae
Plant TypeHerbaceous, perennial
Mature Size12–40 in. tall, 1 –2 ft. wide
Sun ExposureFull
Soil TypeAverage, well-draining
Bloom TimeSpring
Flower ColorRed, orange, yellow, blue, purple, brown, white, pink, many bicolors
Hardiness Zones3–9 (USDA)
Native AreaSouthern Europe and the Mediterranean
ToxicityToxic to dogs and cats

Plant Bearded Iris for a Fantastic Spring Display (1)

Plant Bearded Iris for a Fantastic Spring Display (2)

Plant Bearded Iris for a Fantastic Spring Display (3)

Bearded Iris Care

The most popular of the irises, bearded irises are easy to grow provided you plant them in a sunny site with well-drained soil. A major departure for growing irises compared to other perennials is that they do not like mulch. Mulches (as well as deep planting) encourage the rhizomes to develop rot, so let your soil remain bare. Space plants at least 12 inches apart to prevent the need for frequent dividing.

Though iris do not suffer from many problems, routine lifting and dividing is necessary to combat iris borer worms and keep plants healthy and productive.

Light

Irises need full sun to thrive. Irises in full shade produce fewer blooms and may suffer from an increase in diseases.

Soil

Heavy clay soils do not work well for growing iris, but sandy or gravelly soils are excellent. If your native soil is heavy, you can plant irises in raised beds to help drainage. You may also amend your soil with gypsum or organic matter like compost to lighten the soil.

Water

Although irises like moisture, they also need good drainage to prevent rot problems. Water them when the top 2 inches of the soil feels dry. These plants have a good tolerance for drought.

Temperature and Humidity

Irises are notorious for their hardy disposition. They don't mind temperature extremes, as long as the soil allows excess rain or snowmelt to drain away. Irises that are damaged by heavy winds or hail can be susceptible to iris borer larvae.

(Video) Iris Planting Guide // How to Plant and Divide Bearded Iris Rhizomes // Northlawn Flower Farm

Fertilizer

In the spring, apply a low-nitrogen 6-10-10 fertilizer around your irises. Too much nitrogen will encourage foliage at the expense of blooms. Bone meal is also a good fertilizer.

Types of Bearded Iris

Within the broad category of the popular bearded iris group, there are also subcategories: tall bearded, intermediate bearded, short bearded, miniature bearded, and border bearded. The main distinguishing feature of these subcategories is their stature, although they also vary somewhat in bloom time. Read plant labels carefully so you understand what type of iris you are buying.

New named varieties of bearded iris are developed for commercial sale every year, and the ranking of the most popular irises, conducted annually by the American Iris Society, changes frequently. When looking for irises to plant, it's a good idea to look for those that have won well-known awards, such as the Dykes medal. There are many dozens of fine irises to choose from; here are some award-winners that are widely grown:

  • "Celebration Song" is a pink and lavender tall bearded iris, growing to 37 inches.
  • "Abiqua Falls" is a true blue tall bearded iris that grows to 39 inches.
  • "Again and Again" is a yellow reblooming tall bearded iris growing to 36 inches.
  • "American Classic" is a white with blue-violet iris, a tall bearded that grows to 36 inches.
  • "Beatnick" is a dwarf bearded iris growing to 14 inches. It has purple flowers with white highlights.
  • "Big Blue Eyes" is a dwarf bearded iris with white and violet flowers. It grows to 14 inches.
  • "Dusky Challenger" is a very dark purple iris, growing to 39 inches tall.
  • "Thornbird" is a beautiful yellow iris that grows to 37 inches.
  • "Queen's Circle" has white flowers with blue-lavender fringes. This iris grows to 32 inches.
  • "That's All Folks" is a towering 40-inch yellow-gold iris.
  • "Jesse's Song" is a 35-inch tall violet and white iris.

Plant Bearded Iris for a Fantastic Spring Display (4)

Plant Bearded Iris for a Fantastic Spring Display (5)

Pruning

Faded, withered flowers should be pinched off immediately. This may promote additional blooms or even a repeat bloom period later in the season.

Every four or five years, clumps of iris should be dug up, divided, and replanted in order to cull out diseased roots and iris borer damage. This will keep iris plants vigorous and also allow you to propagate new plants.

Propagating Bearded Iris

Dividing irises not only yields more plants for your garden, but it also keeps your existing irises healthy and vigorous. Here's how to do it:

  1. In late summer, dig up the rhizomes with a shovel, and shake off all loose soil. Any flower stalks that are still in place can be removed at this time.
  2. Carefully pull or cut the rhizome cluster apart into sections. Make sure each section has a fan of foliage; you can trim the foliage off at an angle, leaving 3 to 6 inches of leaves intact.
  3. Examine the root sections closely, and use pruners to cut away any soft, rotten parts. Make sure to cut the roots back past any borer tunnels—you may even encounter living worms, which should be destroyed.
  4. Replant each root section, just barely covering the rhizome. Space roots at least 12 inches apart; they will quickly fill in the spaces. Water thoroughly upon planting, then weekly until frost sets in. New foliage growth will probably begin in late summer and fall, and the plant will grow vigorously when it returns in the spring.

Divide irises every three to five years—or more often if iris borers have infiltrated the plants.

How to Grow Bearded Iris From Seed

Propagation by seed is generally only done by nursery professionals when they are seeking to breed new varieties by careful cross-pollination. But it is certainly possible to grow iris from the tiny seeds found in the green oval pods left behind after the flowers fade. If you collect the seeds and plant them about 1/4-inch deep in the garden, they often will sprout and mature into flowering plants within three years.

But be aware that most garden iris are hybrids, and plants propagated from their seeds usually do not "come true." The iris plants you propagate by collecting seeds may look quite different from the mother plant.

Propagation is almost always done by dividing root clumps—a speedier and more reliable method.

(Video) How to Plant Bearded Iris for Beautiful Results - Bareroot planting.

Potting and Repotting Bearded Iris

Although it's not a common method, you can grow irises in pots that are at least 12 inches wide. Use a loose, soil-free potting mix, and leave the tops of the rhizomes exposed or just barely covered. Make sure not to overwater the plants.

In colder climates, you may need to move the containers to sheltered locations for the winter to ensure the plants' survival. Irises in containers may need dividing and transplanting more frequently than those growing in the ground—about every other year or so.

Overwintering

Trimming back foliage fans to about 6 inches in the fall makes the garden look tidy, reduces leaf surface area that might host fungal disease, and removes caterpillar eggs. Destroy all foliage that you remove, and do not add it to the compost bin.

If plants show signs of rot or damage from borers, the roots should be dug up and inspected in early fall. Cut away any diseased or worm-damaged sections and replant the remaining root sections. Ideally, this should be done several weeks before freezing weather sets in, to allow the roots time to become reestablished before frost.

Common Pests and Diseases

The iris borer is the most serious insect pest of irises. In the spring, caterpillars hatch and tunnel through leaves, reaching the rhizome by summer. Feeding tunnels allow the rhizome to become infected with bacterial rot, compounding the damage. Remove all iris leaves after frost to remove caterpillar eggs, as well. Where rhizomes are penetrated by worms, dig them up, cut away soft, infested portions, and replant the pieces. This is also a good time to propagate your irises by division.

Major disease problems include bacterial soft rot, crown rot fungus, and fungal leaf spot. Mottling of leaves and flowers suggests the presence of mosaic virus.Affected plant material should be removed and destroyed (not placed in compost). Good hygiene is usually enough to control these diseases; fungicides aren't usually needed.

How to Get Bearded Iris to Bloom

When an iris fails to bloom, it can usually be traced to one of four reasons:

  • The rhizomes are planted too deep. When you replant divisions, make sure the crown of the rhizomes are just barely covered with soil.
  • Plants are not getting enough sun. Make sure iris are getting at least six hours of direct sunlight each day.
  • Plants have been overfed. Too much fertilizer causes the iris to put energy into leaf growth at the expense of flowers. A single feeding in the spring is all that irises require.
  • Plants are overly crowded. When root clumps become too dense, flowering will fall off radically. Dig up your irises every few years to divide and replant them.

Common Problems With Bearded Iris

Unique among spectacular flowering plants, bearded irises are largely trouble-free. But do watch for these issues:

Leaves Turn Yellow or Brown, Fall Over

This is usually a sign of root rot caused by excessively wet soil. It can also be the result of extensive damage from iris borers. It is best to immediately lift affected root clumps to cut away any soft, decaying areas and replant in soil that is porous and well-draining.

Flower Stalks Topple Over

Some bearded irises grow as much as 40 inches tall, and staking may be required to support the huge flowers. Irises that grow in shady conditions may get even leggier, making staking a necessity.

Leaves Have Yellow and Brown Spots

Spotted leaves are the result of bacteria or fungal infections. Bacterial leaf spot usually begins on the edges of the leaves, gradually enlarging. Fungal leaf spots usually appear on the inner part of the leaves, and they do not enlarge in size. Affected plant parts should be removed and destroyed. Keep the ground around irises free of mulch and debris. Good garden hygiene usually controls leaf spot diseases. Serious fungal infections can be controlled with fungicides.

FAQ

  • Bearded iris is a mainstay of the sunny border garden. They show best when allowed to naturalize in large clumps. It's generally best to position irises behind other plants that will disguise the yellowing, fading foliage that follows the flowering period.

    (Video) BEARDED IRIS FAVORITES 2021
  • Both types of iris are hardy in zones 3 to 9, and both types bloom in spring. But bearded iris have the larger flowers, with the namesake fuzzy "beards" on the downward-facing fall petals. Siberian iris have smaller flowers without beards, and they typically bloom a little later than bearded iris. The foliage of the Siberian iris is grasslike, remaining attractive in the garden after the flowering period is done. Siberian iris is more tolerant of shade, and the tough fibrous root clumps do not need division as frequently as with the bearded iris.

  • As members of the Iridaceae family, both irises and gladiolus flowers have strap-like foliage and large showy blooms in a wide range of colors. However, the gladiolus is a tender perennial that grows from a corm, and it is not hardy in zones colder than 7. Gladiolus flowers grow in groups staggered along a single stalk, making them valuable cut flowers.

  • If the roots are lifted and divided every three to five years, your iris will continue to live almost indefinitely.

  • Cut the stems when the flower buds are just beginning to open. Cutting in the early morning is best. Submerge the cut ends in a bucket of lukewarm water and recut the stems at an angle, about 1 inch up. Display cut irises in a cool location isolated away from direct sunlight and drafts. Wilted flowers should be pinched off immediately. Check the water level every other day, refilling the vase when needed.

    (Video) Planting bearded iris rhizomes from Schreiner’s Iris Gardens

Article Sources

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Iris. ASPCA.

  2. Dykes medal. American Iris Society.

    (Video) Planting Iris In Pots | Container Gardening

FAQs

Can I plant bearded iris in the spring? ›

Bearded iris can be planted in autumn or spring. If you've bought potted plants, make sure they're planted at the same depth as they were in the pot. If purchased as a bare rhizome, soak the rhizome in water for a few minutes before planting.

Can you plant iris bulbs in the spring? ›

Iris rhizomes can also be planted in spring or early summer, but try to avoid planting them very late in the fall, as they may not overwinter very well.

How long do bearded iris last in a vase? ›

Each flower of a bearded iris lasts about only three days.

When should bearded iris be planted? ›

In areas with hot summers and mild winters, September or October planting may be preferred. We strongly suggest Iris be planted at least six weeks before the first hard frost in your area. Iris should be planted so the tops of the rhizomes are exposed and the roots are spread out facing downward in the soil.

How do you plant iris in the spring? ›

Planting Iris - YouTube

Is Miracle Grow good for iris? ›

Any even fertilizer is fine. You don't want to over-fertilize, because that causes a lot of leaf growth, which may encourage rot, but the fertilizer itself won't. Beardless iris tend to be heavier feeders, thus need more fertilizer, but all irises want a little fertilizer now and then! Miracle Grow is fine.

What happens if I plant iris in the spring? ›

Because you need to cut away the foliage when transplanting rhizomes, the spring is a bad time to transplant iris. Irises flower in spring, sometime between April and June depending on the cultivar, and their foliage does not begin to die back until July.

Can I plant iris bulbs in March? ›

Flowers can bloom as early as February and March, or as late as August, but most varieties bloom in the spring. Iris bulbs should be planted in the fall for spring blooms. For best results, blooms need at least a half day of full sun, but colors will be more vibrant if they receive a full day of direct sunlight.

Which irises can be planted in spring? ›

All About Irises »

A quick guide to growing all the Irises: The big Bearded Irises you plant in late summer, the bulb Iris you plant in fall, and Siberian, Japanese and Louisianas you plant in spring. They're all great, all easy to grow.

What month do iris bloom? ›

Most irises flower from late spring to early summer. Some—mostly bearded hybrids—are remontant, meaning they may flower again later in the summer. The blooming period of Siberian irises tends to follow that of the bearded types. Irises attract butterflies and hummingbirds, and make lovely cut flowers.

How do you cut and display irises? ›

It's best to cut them using sharp secateurs or a knife in the early morning or evening, Some people advise recutting your iris at an angle once they are inside, either under a running tap or underwater in a bucket. Display your iris out of direct sunlight and breezes.

Do iris only bloom once? ›

But while most irises sit out the summer, rebloomers multiply in a frenzy of growth. By late summer or fall, they're ready to flower again. Where the growing season is long enough, reblooming irises are known to squeeze in a third or even a fourth flush of flowers.

Is Epsom salt good for irises? ›

Epsom salt is only good for irises if they have a magnesium deficiency. 'Unless magnesium is deficient (shown by inter-veinal yellowing of older leaves) there is no need to add magnesium as Epsom salts.

How do you take care of irises in the spring? ›

How To Clean Up and Care for Bearded Iris in Spring - YouTube

Do you have to dig up iris bulbs every year? ›

A normal part of caring for iris bulbs is digging them up and putting them in other areas of the garden. Iris plants that are healthy and thriving will need to be divided to keep those blooms popping each season.

How many iris bulbs can you plant together? ›

Loosen the soil to a depth of 4 inches (10 cm) before you begin planting. Plant iris bulbs 1 inch (2.5 cm) deep. You can plant up to 3 iris bulbs together for bunches of glorious flowers. Cover your bulbs with a thin layer of soil.

Where is the best place to plant irises? ›

Where to Plant. Iris need at least a half day of sun. In extremely hot climates some shade is beneficial, but in most climates Iris do best in full sun. Be sure to provide your Iris with good drainage, planting either on a slope or in raised beds.

Can you plant bearded iris in pots? ›

Can I grow Tall Bearded Irises successfully in containers? Definitely. Many gardeners with limited space/town gardens grow Tall Bearded Irises successfully in containers.

How do you keep iris blooming all summer? ›

Follow these tips for the healthiest plants and best blooms: Plant them in a sunny spot in late summer. The plants need well-drained soil and at least six hours of sunlight per day. A full day of sun is even better to keep the rhizomes dry.

How many years will irises bloom? ›

This gives the plants room to grow over the next two to three years. After two to four years, the irises become crowded from new growth and can stop blooming.

Should irises be deadheaded? ›

Iris Care: Deadheading

This prevents the plants from using up their energy in ripening the seed heads. If your irises stop producing blooms, they may have become overcrowded. Dig up the bulbs in early fall and separate them before replanting.

How long do fresh cut iris last? ›

With the right care, iris should last for 5 to 7 days. Upon arriving home, follow a few simple steps to get the most out of your blooms: When you get home, stand the wrapped flowers in water so they can get a good drink while you're getting the vase ready.

Do bearded iris make good cut flowers? ›

Bearded Iris are also an incredible cut flower. They have great staying power in a vase, and if you pick a stem with multiple blooms, the tight buds will slowly open as the older blooms begin to fade and shrivel.

How do I arrange my irises in my garden? ›

How to Plant Iris Correctly for Long Term Success - YouTube

What is the best fertilizer for irises? ›

Irises should be fertilized in early spring about 6 to 8 weeks before bloom, and again after the blooms are gone. Because phosphate is important, we recommend bone meal or super-phosphate and a light balanced fertilizer such as 10-10-10 or 6-10-10 depending on the amount of nitrogen in your soil.

Do you deadhead bearded iris? ›

Not all irises will produce multiple blooms, but bearded Iris varieties and reblooming irises can benefit from deadheading. The process will encourage further blooming throughout the season and make the plant look more attractive.

How do I get my iris to bloom more? ›

How to Get an Iris to Bloom - YouTube

Are coffee grounds good for iris? ›

They prefer a soil pH between 6.8 to 7.0. In fact, you may find that applying coffee grounds to the soil of your iris makes its flowers more colorful. You have an advantage when you compost the coffee grounds here: It attracts the worms immediately.

How do you winterize bearded iris? ›

How to Winterize Iris Plants
  1. Cut back the leaves and stems of your iris plantings with a sharp knife or clippers after the leaves have turned yellow and become droopy. ...
  2. Clear the iris bed of all plant debris including leaves and decaying matter.
  3. Remove the straw or hay mulch immediately if the weather begins to warm up.

Are banana peels good for plants? ›

Banana peels contain: calcium, which promotes root growth helps add oxygen to your soil. magnesium, which assists with photosynthesis. sulphur, which helps plants develop strong roots and repel pests.

Do you cut back irises in the spring? ›

To cut back irises, start by removing the dead flower heads once they have faded and begun to shrivel. This can be done as soon as they start to die off around late spring and early summer.

What is the best mulch for irises? ›

Various types of organic materials are appropriate as mulch, ranging from the widely available but potentially unsightly dry grass clippings or shredded leaves to shredded or chipped bark and wood materials, pine straw, pecan hulls and others.

Do iris plants spread? ›

Irises are perennials, and they'll gradually spread from the roots over many growing seasons. Every three to five years, you'll want to divide the irises in crowded flower beds and replant them to avoid competition for water and soil.

What month do you plant iris bulbs? ›

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.

Is it too late to plant iris bulbs? ›

Bulbs can and should be planted late in the fall just before the ground starts to freeze. Iris rhizomes require planting at least 6 weeks before the first hard frost for the best assurance of winter survival.

How do you plant iris in the ground? ›

How to Plant Iris Correctly for Long Term Success - YouTube

How do you take care of irises in the spring? ›

How To Clean Up and Care for Bearded Iris in Spring - YouTube

Do you have to dig up iris bulbs every year? ›

A normal part of caring for iris bulbs is digging them up and putting them in other areas of the garden. Iris plants that are healthy and thriving will need to be divided to keep those blooms popping each season.

How deep do you plant bearded iris? ›

The rhizomes of the Bearded Iris should be placed just slightly below the surface of the soil, with approximately no more than a ½" of soil covering them. Planting the rhizomes too deeply will only encourage rot.

Do you soak iris bulbs before planting? ›

It is not necessary to soak iris bulbs before planting, especially if you give them a good water once they've been planted in the ground.

Can I plant bulbs in March? ›

When planting in March, it's best to wait until you believe that the last frost is over. The vast majority of the bulbs that bloom in the late summer require sunshine, but make sure to check the instructions for the species that you purchased. Mix in compost and bulb food with the existing soil in your garden bed.

What happens if you plant bulbs in the spring? ›

The roots will then be able to supply the tops with water and nutrients from the soil. Waiting until spring to plant the bulbs will not satisfy these requirements, so spring-planted bulbs will likely not bloom this year. Saving the bulbs for planting next fall is not a wise choice either.

How many iris bulbs can you plant together? ›

Loosen the soil to a depth of 4 inches (10 cm) before you begin planting. Plant iris bulbs 1 inch (2.5 cm) deep. You can plant up to 3 iris bulbs together for bunches of glorious flowers. Cover your bulbs with a thin layer of soil.

How long can iris bulbs be out of the ground? ›

It will not damage the prepared rhizomes to remain out of the ground for two weeks. Select a planting location with good drainage that receives a minimum of 5 to 6 hours of sun every day or that is in full sun. Iris may be planted in a bed or as clumps between other plants.

What type of soil do iris like? ›

Iris will thrive in most well-drained garden soils. Planting on a slope or in raised beds helps ensure good drainage. If your soil is heavy, coarse sand or humus may be added to improve drainage. Gypsum is an excellent soil conditioner that can improve most clay soils.

What month do iris bloom? ›

A number of bearded varieties bloom from early spring to early summer. Among beardless irises, many varieties in the Spuria subgroup bloom from late spring to midsummer. Some Siberian iris (Iris sibirica) and Japanese iris (I. ensata) selections bloom from mid-spring to early summer.

What is the best place to plant irises? ›

Iris Growing Tips

Follow these tips for the healthiest plants and best blooms: Plant them in a sunny spot in late summer. The plants need well-drained soil and at least six hours of sunlight per day. A full day of sun is even better to keep the rhizomes dry.

Do you cut back irises in the spring? ›

To cut back irises, start by removing the dead flower heads once they have faded and begun to shrivel. This can be done as soon as they start to die off around late spring and early summer.

Can iris grow in pots? ›

Iris can be successfully grown in containers. A 6" to 8" pot will work for Dwarf Iris; a 12" pot will work for Tall Bearded Iris. Make sure your pot has good drainage. For soil, we recommend 45% fir bark, 20% pumice, and 35% peat moss.

Videos

1. Iris in the Spring Garden
(Yvonne Confidence)
2. How to Plant and Divide Bearded Iris
(Longfield Gardens)
3. Webinar #23 "Growing Iris in Containers" by Doug Chyz
(The American Iris Society)
4. Low Maintenance Spring Beauty: Bearded Iris
(Melinda Myers)
5. How to divide Bearded Irises
(Beth Chatto's Plants & Gardens)
6. How to divide and plant bearded iris. Start working on the slope in preparation for the raised beds
(Baltic Gardening)

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