How to Plant Bearded Iris for the Best Blooms!
Do you ever wonder if you’re planting your iris bulbs the right way? When I first started growing bearded iris, I quickly learned that how you plant them makes all the difference between a few struggling leaves and a gorgeous flush of blooms year after year.
Now, technically, bearded iris aren’t really “bulbs” at all—they’re rhizomes. But since so many people call them bulbs, I’ll use both terms here. What matters most is getting them into the ground correctly so they stay healthy, multiply, and give you flowers for years to come.
Every spring, my garden is filled with the tall, ruffled blooms of Iris germanica, and they’re always a showstopper. After sharing so many of my iris photos, I realized it was time to walk you through exactly how I plant my bearded iris—step by step—so you can enjoy them in your own garden too, especially if you’re planting them for the very first time.
This post contains affiliate links. If you make a purchase after clicking a link I may make a small commission at no cost to you.
So here’s how I do it, in my sun-drenched beds and cozy borders.
What you will Learn about Planting Bearded Iris Bulbs
- Best time to plant Iris
- Where to plant Iris rhizomes
- How to Prepare your Soil before planting
- How to plant Iris for best performance and what to avoid
- How far apart to plant the rhizomes
- Replanting Iris after Dividing
- Where I buy the best Iris
There is a video of how I plant bearded iris at the end of this post.
Bearded Iris are winter hardy in zones 3-9, so most everyone can grow them with success!
This post contains affiliate links. If you make a purchase after clicking a link I may make a small commission at no cost to you.
When is the Best Time to Plant Iris Rhizomes
Iris are usually shipped from growers in August and September in the U.S. and that is for a very good reason. The best time to plant iris rhizomes is late summer through early fall.
This is why most bearded Iris growers ship out their selections at this time.
This gives most gardeners the chance to get them in the ground so the rhizomes can settle in and the root system develops before the first hard frost or a hard freeze.
This is also the time that you would dig up and divide the Iris currently growing in your garden.
what you need to know
Dividing Iris
If you plant your Iris correctly then in a few years you will need to divide them. Don’t worry, it’s easy enough and keeps your Iris happy and healthy!
After you have either dug up and divided your Iris rhizomes or you have just received some from an iris farm you need to plant them correctly.
This way you will enjoy strong, healthy growing plants with numerous blooms the following spring and early summer.
Where do Irises Grow Best
The best place for irises is in full sun, with at least 6 to 8 hours of sunlight per day. They can tolerate less than half a day’s worth but it’s not ideal, and they won’t bloom well if you don’t give them enough light.
Most recommend planting your Iris bulbs in a dedicated bed or area but I love to plant them in my flower beds and borders with other plants.
Note: You can plant them with other plants that like more water by planting them on a small hill of well-drained soil so they are elevated above the surrounding ground level. They can drain off easily while the other plants get all that water.
This is my favorite tool for digging and planting Iris.
Here is a list of my favorite plants as companions to my Iris.
Prepare the Soil
Clear away any weeds or debris, then loosen up the soil in the sunny spot where you plan to plant your new iris rhizomes.
The most important factor here is good drainage. Irises like their soil moist, but they absolutely don’t want to sit in soggy ground.
Bearded iris generally prefer neutral to slightly acidic soil, though in my experience, they can handle a bit of alkalinity without complaint.
If you’re working with heavy clay, you’ll definitely want to amend it to improve drainage—but honestly, that’s true for most plants.
Avoid Fertilizing Iris when Planting
Here is where I differ from others. I advise you to avoid fertilizer when planting Iris.
The rhizome should have plenty of stored energy so adding fertilizer is not necessary and especially if the soil is well amended each year with compost.
Yet some folks prefer to add fertilizer when they plant. If so then stir the fertilizer into the soil, mixing it in lightly. Don’t just place it in the hole.
Rainfall or watering will deliver the fertilizer where it needs to go if it is stirred into the soil.
If you must use a fertilizer I recommend this one
NOTE: If you struggle with varmints digging up things in your garden then skip adding any bulb fertilizer. Again, avoid adding bulb fertilizer when planting Iris rhizomes.
Why do I avoid fertilizing my bulbs? Many times, bulb fertilizers contain bone meal and that attracts unwanted critters to dig. Or your dog, and bone meal is toxic to dogs!
Remember, unless your soil is very depleted, you do not need to add it at planting time.
The best time to fertilize iris is right after they finish blooming, when the plants are replenishing their rhizomes for the next growing season.
How to Plant Iris Rhizomes
Plant your Iris rhizomes in the soil, making sure to keep them close to the surface.
Note: I have been battling gophers this year. They have been eating my plants including the Iris rhizomes, to deter them from eating my newly planted Iris I put some of this under and around the rhizome.
The Second Thing to Avoid
A common mistake is to bury the iris rhizomes too deep. Iris likes to be close to the soil surface. Leave the top of the rhizome showing, that way I know they are not too deep.
In cooler regions, Iris love the sun on their backs (the top part of the rhizome). If you live in an area with very hot summers, you can cover the backs of the rhizomes lightly with an inch of soil or less.
With the added protection, Iris thrives in extremely hot climates. I grew them in the San Joaquin valley with great success. The climate there is very Mediterranean with hot summer temps.
In cold, cold climates do mulch a bit before hard cold starts but you need to be sure and rake it back as soon as warmer weather begins.
Planting too deeply is the number 1 reason Iris will not bloom.
How Far Apart Do You Plant Tall Bearded Irises?
A good rule of thumb for planting Iris in groups is 6 to 12 inches apart. Good air circulation helps deter fungal disease.
Because Iris thrives here, I leave at least 12 inches so the new Iris can grow and increase. Increasing means making new rhizomes or bulbs you can divide out later for more Iris.
By spacing them a bit further apart there won’t be a need to divide sooner than in 3 years.
Replanting Iris after dividing
If you want to know how to divide Iris then you can read all about that here.
When replanting a particular Iris that I have divided, I like to plant three rhizomes together. That gives me a spectacular mass of blooms in Spring.
Plant them with the pointy noses of the rhizomes facing each other in a circle. Spacing is not critical, but I like to place mine about 6 to 12 inches apart for the reasons stated above.
I firm them in with my foot, you can see my footprints in this photo.
Planting them this close together means you will get a good show of blooms next Spring but you will also need to divide them sooner than if you planted them further apart.
Above the soil is moist but if you are doing this during a drier part of the year water them in and keep the soil moist through the summer but not soggy.
If you are planting a newly acquired rhizome you will most likely only have one, and that is fine. Plant it the same way.
In a few years, you will have enough to divide and replant.
Next Spring you will have some lovely Iris to enjoy.
Most reputable Iris farms and gardens send out good-sized, high-quality bearded iris rhizomes that will bloom the first year. If you visit an Iris farm, many have new plants in pots too.
When dividing your Iris, you may have some smaller-sized ones attached to the larger rhizomes.
The smaller ones will take another season to grow in size before blooming. So don’t get discouraged if yours doesn’t bloom in the first season.
One pest that can damage Iris is the Iris Borer, read here for more about that. Iris borer can lead to bacterial soft rot.
I hope this helps all those out there who were skittish about growing Iris. Growing Iris is truly very simple and so rewarding.
Watch this fantastic video tour of my Iris in their full glory!
Where to buy Iris Bulbs Rhizomes
My favorite Iris Sources are:
Schreiners Iris Gardens
Suttons Iris Garden
Happy Iris Planting!
More to come on Siberian irises, Japanese irises, and other iris varieties you can grow.
Hi, I’m Pamela
With 45 years of hands-on gardening experience, I love sharing practical tips, proven techniques, and inspiration drawn from my own gardens. My goal is to nurture your confidence, spark your passion, and help make every step of your gardening journey more enjoyable.
They may grow for you just plant them now and keep them watered until rainy weather arrives. They are tough as nails and you may be surprised.
I have dug up many of my Bearded Iris & they have been left in a box outdoors. Are they still viable and if they are a little dried out, is there a way to “reconstitute” them?
Thank you
Yes, trimming the roots should not be a problem but whether they bloom or not depends on the rhizome size and maturity.
This is the first year I’ve dug up my iris (I’m moving) I cut off some of the roots but not all (just rimmed) is that ok and will they bloom
Thanks so much for the great tutorial on dividing and replanting iris. Very simple to follow and really informative
After blooming and in the fall, do you cut the leaves down?
I just started with 25 dwarf iris this spring ,they are lovely in my pots will certainly grow lots more now ,will try full size ones ..
I have an area in the garden that I just set them in and toss some soil on top, no need to plant deeply as long as it is well draining. If I have extra of one variety I usually give those away and many times I have actually potted them up in one gallon containers as well.
How do you store bulbs if you have to many to plant? I have so many not sure what to do with them all.
Thank you
Shar
Burns TN
Not usually, divide rhizomes to keep them true though they can throw out a sport from a rhizome, though it is usually a parent. Seeds from Iris are a different story, they will cross pollinate and if you let them go to seed then germinate them they will be a different variety. That is how they get some many different colors.
Will irises of different kinds “mingle” or create a different plant if they are planted close to each other?
Thanks
Hi, Pamela. I just finished watching your video where you dug and transplanted your irises. Thank you, thank you … your video is the only instance that shows how to position the iris corms when replanting. So now I will remember to plant mine with the leaf fans outward and the corms facing in. Happy gardening, Pamela. 🙂
Does anyone out there know where I can get the iris “Tiburon”? I had it before but have lost it and would very much like to acquire it again. Thx so much for any help.
This information is fantastic, thank you! This is my first season planting iris– wish me luck! I ordered from Schreiners & the bulbs that arrived look very healthy! I hadn’t heard of Supersition Iris–like I said, I’m new to this– so thank you for the referral! Their website says they mail out a description-only catalog, which sounds downright adorable. I’ll be signing up for that! 🙂
I am in Northern Calif and we are still getting rain and snow. I had to contend with Bermuda when I lived near Stockton, it is a pain in the patoot. If you just get the foliage when spraying then Round up is a good choice. Yes I do prefer organic gardening but there is a lot of misinformation about Round up out there and using it judiciously is less harmful than some of the much touted vinegar and Epsom salts recipes. Do more research on those and you will find they do not break down and are washed into water ways and can do damage to the life forms in the soil that you really want to keep healthy.
You will be fighting the Bermuda for the rest of your days. Thankfully here in the mountains it is too cold for it and it won’t live.
. My iris only bloomed sparsely this year – definitely time to divide them. Thank you for your video and what kind of fertilizer to use. Mine are going to a new spot in my garden.
We used cardboard across the entire small lawn area and killed all the grass. Now we have nonly chips and wonderful low-water native plants. I live in California where we have a constant drought (except lots of rain this year).
My neighbor has Bermuda grass that is constantly in my garden. I once did a “no-no” and sprayed the leaves with Roundup. I protected the soil and adjacent plants and just got the foliage. It seemed to help
I love irises! I had a large collection of them. After reading this post I believe that what I had suspected happened to them did happen to them. I live on a slight hill. My neighbor up hill washes his cars (3) every single day! I’m certain he contributed to their demise.
I cannot wait to start planting them again, with your tips!
Thank you!
I am not sure of what you are speaking. I do have a filter on my comment section that automatically sections off suspected spam, many times it can be when a URL is attached to the comment. You would not believe how much spam gets posted to the comments section. Many of them redirect people to objectionable sites. This blog is open to everyone that loves to garden. Sorry if you feel slighted.
P
Thank you Pamila
Thank you…I see you censored my comments….but that’s OK. I WAS only looking for information on planting Irises, which you supplied…thanks again, they give me joy.
THOMAS
P.S….what is a spammer? Or is this only a women’s club?
This is great information! I love iris and pinned this article for reference.
Hi Barb, I don’t do much as I am in Zone 8 and they do just fine without my help. I can only relate what I have read about mulching after first frost. Are you saying the leaves of the Iris is what is tough to take out? If so you can certainly cut them back in late Fall. They will have absorbed all they can for building blooming energy. Around your average first frost date or a little before is fine. My new transplants of Iris all have their leaves cut off to prevent them from toppling and they do just fine.
Could you please tell me how you prepare your Iris for winter. I’m in a zone 3-4 and have a huge bed of iris which I cover with clippings from the juniper plant every year. But what drives me crazy is trying to pull out all the old, dead, soggy leaves in the spring. Would really like to hack them down if that won’t kill them and if so, how short? Love your blog.
Hi Amy, here is the entire collection of my Iris Posts for your reference and since I have never stored Iris over the winter here is an article that may be helpful to you. Storing Iris Rhizomes
I hope this helps.
We moved to TN last year. Zone 7. I have an over abundance of the variety of Iris the previous owners planted. They need to be split and I’d like to add some variety to the garden. How long can Rhizomes be stored if you can’t plant them right away? What is the best time of year to plant? We do have a garage that stays over 50 so we could prevent them from freezing.
Love your irises….they are such an easy care flower and so easy to transplant!
If they froze thru, you may not get any but you should be able to tell by touching them. If any of the rhizomes are solid, not mushy then they should be fine. Go ahead and replant the nice solid ones when you can and you should see them come back just a pretty as they were before. Iris are fairly sturdy.
I love iris and have many colors. Here is my question. In the fall I dug up an entire bed one weekend in hopes to
relocate them. At that time we were taking care of my ailing father and we never got back to putting them in the
ground. My Father died in October and this winter in Missouri has been harsh and extreme .Needless to say
the iris never got planted. They have been sitting on the floor of a shed like building with all the elements hitting them. Do you believe it is still possible to re-plant them and see if they will grow? I have found that it takes two years for the blooms to re-appear. Any help would be appreciated.
Dig up sod, ha ha ha…what a waste of time. I just dump a big pile of compost in that area and make a raised bed. I might, but rarely, put down some newspaper or cardboard first but really who even needs that. The deep compost kills out any grass and the worms dig up thru and turn the dirt for me. 🙂 I should not say any grass. When I lived in the San Joaquin valley I had Bermuda grass, ugh, that would not die from being buried underneath anything, but neither could you dig it up enough to kill it. The roots went down 15 feet. Hated that stuff, but it won’t live up here. Hurray!
Good post….and I am with you on the “Gardening Rules”…I hardly ever find myself following them. I move hydrangeas when I need them moved, I never, never never break my back removing sod/grass to make a new planting bed, I cheat!
Your irises obviously love your rules!
XO,
Christine
You are welcome Joani. Iris are great as they give lots of bang for the buck and are tougher than nails.
First of all Miracle Grow is too high in nitrogen and is not the right choice for Iris. Just make sure they are not buried too deep, get watered and I use bone meal as it is low nitrogen, high in phosphorus, which Iris seem to like. The site where I get my Iris has a fertilizer specifically formulated for Iris and may be your best bet, though I have not tried it myself. Shchreiners Gardens…here is the link, I hope it works so you can just click it. http://www.schreinersgardens.com/iris-fertilizer
Love Iris…but for some reason I don’t have any in my yard. I have to remedy that. Thanks for sharing all of your knowledge.
thank you so much for this information! I have several Iris plants that were my mother’s! Usually every mother’s day I would have at least one purple Irish that would grow at that time. It always made me think that my mother was watching over me. I have since moved from California to Fort Mohave, AZ. My plant took a beating from the move and I am trying to save these few plants I have left because they mean so much to me. I have been feeding them miracle grow in hopes it will revive them soon. Can you give me any instructions or ideas to help me save these plants? I would be so grateful and happy if I can save my Mother’s plants!
Thank you for your posts I love following you on here and on Pinterest
You are welcome and you will fall in love with gardening. Just remember to take little bits at a time and don’t overwhelm yourself. This overgrown patch of mine was a bare mud hole when I began and I took one 4′ x 4′ spot at a time and enjoyed my accomplishment on each one before moving on to the next.
Just found your blog from Hometalk and am having fun looking around. I live in a city in the high dessert at 5600 feet which sounds a little like your climate. Most people who blog about gardening are in more humid areas! For years I thought I hated gardening and yard work and so didn’t pay any attention to the yard. The past couple of years I’ve realized I do like working in my little yard but am having to overcome 20 years of so so attention. I love my Iris and will have to separate them this year. That would take care of that empty space next to them! Thanks for the info.
I got it from Schreiners Gardens. They are a very good Iris breeder, I have always been impressed with the quality of the rhizomes I receive from them.
Necessity is truly the mother of invention. I have to do garden chores when I have the time or when I moved just dig up and take them with me despite it not being the “right” time of year. Sometimes I did things by accident and they worked. So it is a matter of trial and error. But what fun it is. We are to have a HOT day today, it will be near 100 here on this mountain, which is RARE indeed. But then it will cool down by Monday, which is better for the garden. I could use a good rain to water my garden right now. Enjoy your rainy weather, the sun will shine again for you.
I have read about that but haven’t experienced it. Yet, you never know when something crops up to make gardening challenging. I have these needle nose beetles that wreak havoc on my rose buds in the Spring, they showed up for the first time about 3 years ago. I go out each morning with a jar of soapy water and knock them off into it, it reduces the population enough to save my blooms then they are gone suddenly. But they return the following Spring.
You are so like me, with your methods of gardening, we both love our gardens but don’t plant or do things to the book !!
I wish I lived near enough so that I could have some of your give away Iris. What lucky friends you have.
We have enjoyed a week of lovely warm sunshine & now for our weekend the temp. has dropped & it’s raining, oh. well one things is I don’t have to water the plants.
Enjoy your week end.
Beautiful, beautiful. I also roll my Iris rhizome in sulphur before replanting. Iris are predisposed to a nasty virus here in my area and the sulphur helps to keep them healthy.