Myths and Facts about Iris

A few words about the author:  Lee Kaibel is a Dakota County Master Gardener who has lead the iris committee.  


Tang Fizz



 Myth – I do not grow Iris because they have a short bloom time.

Fact – By using different types of Iris you can lengthen the amount of time that irises will be blooming in your garden. Miniature dwarf beards and crested iris bloom in early May followed by the rest of the bearded iris cultivars which bloom the full month of May. Next in bloom is the Siberian Iris which blooms in early June and is followed by Yellow flag iris, Blue flag iris and Japanese iris which all bloom in mid- June.  By using different types of iris you can have about six weeks of bloom time.


Myth – Are there really Iris borers?  I have not seen any on my bearded iris, what do they look like?

Fact – Iris borers are very destructive as they feed on the iris rhizome. They can destroy   all or part of a rhizome by introducing bacteria and causing soft rot in the rhizome as they feed.  Clean up all debris in the fall as that is where the Iris borers

Iris Borer

For more information on Iris Borers and how to manage them use this link:

Myth – I lost some bearded iris last winter they must have not been hardy for zone four.

Fact – Winter loses are not due to cold temps. The rhizomes sit right at the top of the soil line.  This will expose the rhizome to the wind if there is no mulch or snow covering it. The rhizome will die from the wind dehydrating it.  Blue flag irises which are native to Minnesota are so hardy they can freeze into the ice on lakes or ponds and still survive the winter.

For more details on  types of iris, heights, bloom times and colors check this link:

Remember to enjoy these spring blooming beauties they need to be planted August – November the year before.

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