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Iris – Perennial Bulb with a Majestic Appeal

Iris is one my favorite flowers when it comes to growing perennials.  I remember that my mother used to have them in all her garden beds, and when I see them now, I get very nostalgic. 

What I love most about irises is the color they, and other early spring bloomers, bring to my garden.

Keep reading to find out how to grow these pretty plants.

Colorful irises in a field.

Iris – Easy to Grow Perennial Rhizome is one of my Favorites.

Many people consider irises bulbs but they are in fact rhizomes.  A rhizome is a horizontal stem, usually under the ground that sends out roots and shoots from the nodes that form on it. They are also called root stalks.

Irises are easy to grow if you keep a few basics in mind. They are quite drought-tolerant and normally very low maintenance. I have some in my garden beds here in North Carolina and they never seem to fail to appear in the spring.

Flowers of irises

The plant has beautiful large flowers in the spring. It can also surprise the gardener by occasionally blooming again in the fall if conditions are right which is a delightful treat.

Colors of the flowers vary but common ones are purple. You can get them in pink, orange, yellow, blue and even multi color varieties.

There are even varieties with blooms that are so dark that they look like black plants.

 Here is one of my bearded irises in full bloom.  These were planted by an old well casing a few years ago and I transplanted them from my mother’s garden.

They are gorgeous now and bloom everywhere in my yard.

purple iris with a yellow throat

Cold hardiness of irises

The rhizome is hardy from zones 4 through 8 and  

Soil and sunlight needs of iris bulbs

Irises are not particular about soil and will tolerate anything from sandy to loamy soil. Don’t use high nitrogen fertilizers and be careful about careless mulching which can encourage rhizome rot.

They can take  either full or part sun. The rhizomes should be kept exposed. 

They need a bit of sun and air to dry them out and will rot easily if they are covered with soil or crowded.

LIlac Bearded Iris

Pruning irises

Don’t trim the leaves when flowering is done.  These are needed to carry the photosynthesis for next year’s growth.

Cut off brown tips though—and cut the flowering stalk down to the rhizome to discourage rot.

Yellow bearded Iris

Division of irises

Divide after 2 to 5 years when the clumps get crowded. If you don’t do this, you’ll end  up with a patch that had a center with no blooms.

Divide them soon after bloom and then transplant to places where the roots will be moist but the top quite dry.

Varieties of irises

There are so many irises to grow. They come in all colors and sizes. Some will even rebloom.

Here are a few to try:

  • Ozark Rebounder. Zones 3-11, Blooms in both spring and fall in  zones 5-10.  It will attract hummingbirds and butterflies too.
  • Sapphire Beauty.  The deep yellow throat looks amazing on the purple petals. It blooms in summer and is deer resistant.
  • Princess of Corinth is a pretty pale peach re-bloomer that is deliciously fragrant.  It is hardy in zones 3-11 and will re-bloom in the summer/fall in zones 5-10.
  • Orange Harvest does the name justice!  The colors practically scream fall!   It blooms spring, early summer and fall.  This one can take sun or part sun and is drought tolerant.


Aren’t my mother’s irises lovely?  They formed big clumps this year.  See more photos of these irises here.

Irises blooming in a garden bed.

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Thursday 10th of August 2017

I live in Michigan. When is the best time to plant the rhizomes? How long before they will grow and bloom? Is it ok to put natural mulch or rubber mulch over them in the flower bed? Thank you, I've been trying to grow Irises for a long time and I have had no luck. I would maybe get one bloom but these were from re plants so I would like to try from the rhizomes.


Thursday 10th of August 2017

Hi Kathy. My mother lived inn Maine, which I assume is similar in climate. She planted hers in the early spring, or late fall. irises will stop blooming if they get too crowded. Keep the mulch away from the crowns of the plants. Carol


Monday 1st of May 2017

Hello Carol, I really appreciate your tips on irises, and the pictures are lovely. I am a painter and have been painting mostly irises lately. I have saved some of those you posted here to use as reference material in future. THANK YOU!


Monday 1st of May 2017

My pleasure Kathy. I'd love to see some of your paintings! Carol


Wednesday 26th of April 2017

I agree with Carol for most of 90% of her comments & the rest might score 100% depending upon where she lives in the US or other countries - which all grow healthy irises.


Wednesday 20th of April 2016

My neighbor gave me many rhizomes to plant and I have never really planted anything. But have been reading some info and on a bulb planting guide it says you should plant them 5 inches deep and then I see that the rhizomes should be partly exposed to the sun . Could you please give me some tips on planting these future beauties? They are the small deep purple Iris with yellow down the middle of the petal. I have an area that will get full sun if I plant them there and then I want to plant some in part sun , as I have read either is fine. Thanks so much for your time.



Wednesday 20th of April 2016

Hi Heather. My experience is that the Irises are very forgiving. I had some growing near a well that got full sun and NO water and the rhizomes were exposed to the sun because of soil erosion. They flowered every year. I dug them up and planted them throughout my borders. Some get full sun, some part sun. Some have the rhizomes near the soil and others are buried deeper. All flower beautifully every year. I would cover them with several inches of soil. The ones that I did that with are growing the best and multiplying each year.


Jennifer Smith

Thursday 7th of November 2013

Iris are not grown from a bulb. They are a rhizome. Thank you.


Thursday 7th of November 2013

Hi Jennifer/ Thanks for pointing that out. I've adjusted the wording on the article slightly. Carol

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