For the Love of Iris

Articles, Tips and Notes from Schreiner's Iris Gardens

Bearded Iris Grow Strong All Summer Long


Summer days, summer gardens. Most enjoyable. For the Tall Bearded Iris in your garden, summer is also the perfect time to grow, to expand, to be transplanted.

Planting IrisBearded Iris experience two root growth cycles in their annual growing cycle. The springtime growth we all eagerly anticipate in our Iris beds begins with the lengthening of the foliage upward and the root system outward. The rhizome uses its stored-up nutrients.”….As the bud swellings appear in the new fans there is a quickening of the new roots that will supply the plant with nutrients for new growth during and after bloom. The old roots from the previous year’s growth then wither and decay.” ( The World of Irises, p 314)  After the springtime color display of full bloom has passed for the year, the underground development begins in earnest.

The Iris revel in the long summer days. During the six to eight weeks post bloom, the plants absorb the necessary nutrients for next spring’s growth and bloom. The rhizomes send out new increases which will become new self-contained, self-supporting rhizomes by early to mid-July. Once the summer growth is complete, the Iris takes a well-earned rest. Enter the gardener, spade in hand, plan in mind. Now is the time to dig, divide, share and transplant.

HowIrisDivide-webHere, in the Willamette Valley our Iris bloom season ends early- to mid-June. Therefore, at Schreiner’s Iris Gardens, we begin digging our fields early to mid-July. On a smaller scale in your garden, consider digging your Iris to transplant this summer if the clump is three to five years old. Share the divided Iris not only in your own garden, but also with the neighbors, friends and family….garden clubs, retirement homes, 4H clubs, and so on. Allowing Iris clumps to become over grown can lead to poor or no blossoms, smaller and smaller rhizomes, and outbreaks of rhizome-based diseases (such as bacterial soft rot).

Remember that the latest date for transplanting depends on local conditions. Newly planted Iris require a minimum of 6 weeks to set their new roots. Thus, they should be in the ground a minimum of six weeks before the first hard frost. Consult local resources to determine the frost dates in your area.

Dividing Bearded IrisSo, how do you go about digging and dividing the Iris in your garden? Visit our “How to Grow Iris” pages for more details and images on dividing and caring for your Iris! Take a look at another great Iris care resource, “A Guide to Bearded Irises: Cultivating the Rainbow“, by Kelly D. Norris.

Iris | Iris Fertilizer

What’s happening in the July garden? To trim or not to trim the foliage…Depending on your location, you may have a handful of lingering Iris blossoms, or all of your bloom stalks might be sporting the papery remains of the seasons’ blooms. When all blossoms on the stalks have finished, carefully trim the bloom stalk at its base. Leave all green foliage, though, in place. They offer an elegant vertical visual throughout the garden. You may remove any browned and dry leaves. Keep the Iris beds clean and free of weeds. Well-established Iris plants are drought tolerant. Newly planted Iris, though, do require a good long drink approximately every 7 to 10 days if the weather is very dry. Reblooming Iris also prefer irrigation between the spring bloom and summer/autumn re-bloom times. We recommend an application of a low-nitrogen fertilizer (such as 6-10-10) approximately one month after blooms have finished. Superphosphate and bonemeal also work well as a fertilizer for Iris.

Discount IrisSummer brings the promise of long days enjoying our gardens and all aspects of our lives. The season also brings with it our annual Summer Sale. You’ll find over 300 varieties of Tall Bearded Iris at deeply discounted prices.


Author: Schreiner's Iris Gardens

Growing beauty since 1925. Retail and wholesale supplier of high-quality Bearded Iris & Daylilies.

22 thoughts on “Bearded Iris Grow Strong All Summer Long

  1. I bought Bearded Iris and set out in September. One bloomed in January. Could it be that our soil was still so warm. The other two have not bloomed. Should I expect the regular bloom in the Spring?


    • Depending on your location, the warm soil or warm weather pattern could have triggered the bloom cycle. We hear that in areas of Southern California, Iris bloom virtually year-round. Of course, bloom depends greatly on variety, soil conditions, weather, etc. The other Iris, assuming they currently are showing healthy foliage, are likely to bloom in this spring. If not, do not dismay. Approximately 75% of newly planted Iris bloom the following spring. The others require an additional year to put up bloom stalks. Keep us posted!


  2. Here in South Carolina along the coast, we experience soft rot when we have a wet season. This results in a loss of many iris. When the remaining ones bloom in the spring, you know it was worth the effort.Having gone to the National Iris Convention in Portland this year for the first time, seeing the peak bloom season at so many gardens, it makes me want to keep growing . Hope to get to New Jersey for the 2016 Convention!


    • Hello. Thank you for sharing your story of perseverance with Iris growing despite the odds that nature sometimes deals to you. Do the surviving Iris avoid the rot because they are located in an area with better drainage? Or do you feel they might be sturdier varieties compared to the Iris that suffer the rot?


  3. I Have pretty much followed all instructions for growing these majestic flowers with some degree of frustration. Houston heat is a real challenge and general comments of their beauty is not helpful. Many Texas nursery folk tell me I am wasting my time. Region specific help would be the minimum help needed from the experts. All some recommended dryness and sun has created is a wilting plant.
    My plants are one year old and yielded on e flower soon afte planting in September last.

    Schreiner responses are certainly encouraging sign.


    • Hello. Thank you for writing. It is true that the instructions we supply generally apply to temperate zones. Extremes at either end of the temperate zone temperature scale would require adjustments to the growing instructions. Information we have gathered regarding growing Iris in areas with extreme heat suggests providing some shade for the Iris, more than what we would normally recommend. In addition, more water is beneficial in areas of extreme heat and dryness, particularly for newly planted Iris. Additional water throughout the year has been found to benefit the Iris in their yearlong growth cycle. You might try contacting the American Iris Society Region 17 folks, who are all located in Texas, regarding the best growing practices for Iris in the Houston area. Tom Burseen and others have all had success growing Iris in Texas. Here is a link to the contact information for Region 17: Best of luck to you. We invite you to continue to share with us your experiences growing “this beautiful flower” in your Texas garden.


      • Quite heartening to get a response. I assumed some of these suggestions and implemented some measures.
        Thanks for your help.


      • Yes, I agree with both the sender and the response. I am in Southern Calif= san Diego County with high desert and drought. I do have my Iris in semi shade as it is just too hot. I will check out the link provided. maybe there is one for my area.
        Tnx, Candy


  4. I am sad to say that not one of my Iris bloomed that I purchased last year. It has been extremely disappointing. Has anyone else had this experience??


    • Hello, thank you for sharing. How unfortunate that you did not have blooms this spring. Lack of bloom can be a symptom of various circumstances, including inadequate sun, poor soil nutrition, overcrowding. If the Iris were planted just one year ago, it is possible that they simply need another year to become better established. If this is the case for your Iris bed, we recommend applying a low-nitrogen fertilizer about one month before the spring bloom. If you suspect there is a different problem, we suggest visiting our “how to grow Iris” pages for more information and possible solutions. You are also welcome to phone our Customer Service at 800-525-2367, Monday through Friday, 8:00 a.m. to 4:30 p.m. (Pacific), to discuss the lack of bloom and possible solutions.


    • I have had almost the same experience. The Bountiful Harvest bloomed in the spring, but Eternal Bliss, Again and Again, Buckwheat, Autumn Circus, Berry Fulfilling and What it’s Worth have sent up vigorous foliage but NO blossoms. Did you get any other responses? I have religiously followed the planting and fertilizing directions and an very disappointed.


      • Hello and thank you for the comment. It is good to hear that your spring blooms were successful. Re-blooming Iris have been known to have unpredictable second bloom, though. This characteristic, while sometimes frustrating, contributes to the joy and excitement experienced when second bloom does take place. You might try visiting the website of the American Iris Society chapter on Reblooming Iris: There you will find great information, especially under the link referring to “Culture”. Best of luck and keep up the faith!


      • Hi William. My last comment was to Jamshed Elavia in Houston. I, too, am very disappointed. But the good news is they are still alive, so there is hope… 🙂 I haven’t had time yet to go out and work the soil again or to read the link information, but I will. Thanks for the comments back. I am glad I am not the only one, not that I wish ill on anyone’s flowers, but just that I am not the big black thumb I feel I am … hehe


  5. How do you or when do you divide the re blooming irises?


    • Hello and thank you for writing! We recommend dividing re-blooming Iris every 3 years. Non re-bloomers can be divided every 3 to 5 years. Use a low-nitrogen fertilizer or bonemeal at the time of transplanting. Water in well once every 10 days during times of no rain, until the fall/winter when rains return on a regular basis. Fertilize about one month before bloom season in the spring, and again about one month after spring blooms have finished. Happy Gardening!


  6. Here in Texas, transplanting waits until late September since our first frost will be sometimes in November.


  7. It’s always fun to talk about irises, we had a very wet bloom season, everything bloomed, but we now have some leaf spot and rhizome rot. Just now starting to dig and split, and start a new bed, as we live northern WI. this has to be done sooner. waiting on my dwarf shipment. We had no winter losses. happy blooms everyone.


  8. My first tall bearded to bloom was “Footloose,” and the last one finished blooming last week, “Fluffy Pillows.” Although we suffered rain & wind damage this Spring, over 82% of my iris bloomed. What vigorous rhizomes you have !!!


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