Bearded Iris: The Most Popular Flower With the Most Colors

What's your favorite color? Is it one that you have a hard time finding in flowers and plants for your garden? Perhaps your landscape is seriously lacking a specific color. Or maybe you just want ALL the colors. Every single one.

Look no further than the bearded iris to fulfill all your color-rich dreams. Even if you're not a fan of human beards, you're sure to fall in love with the frilly falls of this flower. Not only is it one of the most popular blooms, it has the added benefits of a multitude of colors and easy care instructions.

If you need a certain splash of color to add to your garden art or you just want to be part of the popular crowd, the bearded iris is for you.​

Bearded Iris Overview

Common Name(s)Bearded iris
Scientific NameIris x germanica
FamilyIridaceae
OriginEurope
HeightUp to 30 inches
LightBest in full sun, but grows in shade also
WaterMedium
TemperatureAbove 40 °F
HumidityLow-medium
SoilFor soil, 45% fir bark, 20% pumice, and 35% peat moss.
FertilizerUse low-nitrogen fertilizers
PropagationDivide ans break off seedpods that form after the blooms have faded.
PestsBorers, verbena bud moth, whiteflies, iris weevil, thrips, slugs and snails, aphids, and nematodes

The bearded iris plant has a fascinating mythological origin story. The Greek goddess Iris would descend to Earth on a rainbow to deliver messages from the gods to the humans. Wherever she landed, varicolored flowers sprang to life. Makes a lot of sense, knowing that “iris” is the Greek word for “rainbow.” And you could definitely grow your own rainbow using just irises.

Their normal, everyday history is no less fascinating. The Egyptian King Thutmose III conquered Syria and brought back irises to his garden. (My kind of king, digging plants instead of gold.) To the Egyptians, irises stood for life essence and renewal, so it's no surprise they used the rhizomes to make medicines and incense for religious rites.​

They came to America with European settlers in the 1600s but they were especially adored by physician and professor Michael Foster in the late 1800s. His student William R. Dykes really brought about the iris' advancement with his book The Genus Iris.

Types of Bearded Iris

The American Iris Society recognizes eight different groups of the bearded iris: Tall, Miniature Dwarf, Standard Dwarf, Intermediate, Miniature Tall, Border, and Aril or Arilbreds. Investigate the different groups and see which ones most appeal to your tastes.

For example, maybe you like the Tall group for their height and their later blooming tendencies. Want a purple bearded iris? Check out “Afternoon in Rio.” Looking for more of a white bearded iris? Take a peek at “Winterfest” or “White Hot.” If you want to express your darker side with a black bearded iris, try “Anvil of Darkness” or “All Night Long.” Even the names can give you happy shivers.​

And those are just a few examples from a single group. With eight groups, you're sure to find exactly the right match for you and your garden.​

Bearded Iris Care

Another reason for the popularity of these prolific pretties is how easy they are to care for.

Planting

Peach-colored bearded iris. source

Best time for planting rhizomes is between July and September. If you live in a hot climate or have light soil, cover the rhizomes with an inch of soil. Otherwise, plant with the tops just above the soil. Since irises prefer a good amount of air circulation, plant them about 12 to 24 inches apart. This will also save you from having to separate them in two or three years. You may get quicker results and deeper colors planting them closer, but you also run the risk of encouraging and spreading disease among them.

A good method for planting rooted rhizomes would be making a four-inch deep hole with a little mound in the center. This way, you can spread the roots over the mound and then gently tamp down the soil around the roots.​

Light

Irises love six to eight hours of sunlight daily. As long as you're not in a hot climate, find a spot where the full sun will hit them. Too much shade will prevent the blooms from happening.

Water

When in doubt, err on the side of inadequate when it comes to water. Fewer deep waterings are better than many shallow ones. When newly planted, water when the top three inches of soil dries out. After the first rain, you can adjust your schedule.

Soil

Drainage, drainage, drainage. Like many plants, irises hate standing water and soggy roots. One good way to assure adequate drainage is to plant on a slope or in a raised bed. Adding compost to the soil can improve drainage as well. Add some gypsum to heavy clay soil. Add sulphur if your soil is too alkaline (irises like it acidic at 6.8).

Fertilizer

Avoid nitrogen fertilizers which can encourage growth more susceptible to disease. A good one to try is salt-free alfalfa. Irises don't need fertilizer often, just a light application in the spring and one more when they bloom. If you have a reblooming type, you can fertilize at the second flowering as well.

Pruning​

In the fall, cut back the leaves to six inches over the ground so the iris can use its energy for root growth instead of winter foliage. Remove any damaged or dead leaves any time you've a mind to.

Propagation

After three or four years, it may be time to separate crowded irises and replant them with more space around each of the bearded iris bulbs. A good time to do this is when they are dormant in July or August. You can break apart the rhizomes or cut them with knife, leaving a fan of leaves on each one. Trim the leaves to three inches and leave the bulb in the shade for a few days to a week. This will allow the cuts to heal before planting.

Problems

Diseases

There are a few diseases that can strike your precious iris plants so keep an eye out for these afflictions.

Rot – There are several different kinds of rot that irises can suffer from, either bacterial or fungal. Bacterial soft rot gets in through cracks in the rhizome and makes leaves wet-looking and nasty. Avoid damaging rhizomes and destroy any affected plants. You may need to replant in a different area and disinfect your garden tools.

Sclerotic rot is caused by a fungus, as is botrytis rhizome rot, and can occur in overcrowded plants. Both types can overwinter in the dirt so you will need to either remove and replace the soil or move your irises to a different spot. You can also try a fungicide like Chlorothalonil.​

Leaf Spot – This includes Rust, which shows as dark red spots, and Bacterial Leaf Spot, which displays green watery streaks and dots that eventually turn yellow. Destroy the affected leaves. If you are already aware of leaf spot issues where you live and grow, apply fungicide every couple of weeks when the leaves appear until the plants stop growing. Get rid of damaged foliage in the fall.​

Mosaic Virus – Aphids are known to transmit this disease so controlling your aphid population will help keep your plants safe. You'll notice a mottled pattern on your flowers and possibly streaks on the leaves. Burn the ones with severe damage.​

FAQs​

Close-up of a yellow bearded iris. source

Q. There are some new iris plants in my garden this year and they don't look as good as the original ones I planted. Why is that?

A. You might want to consider breaking off the blossom stalks of your original plants right after the season. This will avoid the problem of the cross-pollinating by bees that results in seedpods dropping. The flowers that grow from these pods usually aren't as attractive as the originals.

Q. Why didn't I see any blossoms this first spring?

A. If you live in a temperate zone or if you planted immature rhizomes, these may be reasons why you didn't see any flowers this time.


Whether you favor one particular hue or want to embrace every color known to gardeners, your rainbow fantasies can thrive with the bearded iris plant. No matter how diverse your circle of friends and family, you'll discover their perfect iris match somewhere. Then you'll revel in the joy of bringing those pairs of people and flowers together, making the world a better place one iris at a time.

Share your stories and pictures of tearful and happy iris rainbow connections in the comments. Any questions you may have are welcome, too. Share this article with friends who doubt the power of the iris and show them the error of their ways. And as always, thanks for reading!Jump to top​

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