What Is Wrong With My Iris Plants This Year?

Question

I have a large stand of iris that in the past have bloomed like crazy but this year, I only had about 12 blooms and there are yellow spots on the leaves. My neighbor’s iris leaves also are showing signs of these yellow spots. A Google search suggested it may be a fungus so I treated my patch with Garden Tech Daconil Fungicide but it did nothing. The leaves are turning brown and dying off now too. I have no idea what to do and sure don’t want to lose my entire patch of iris! Any help is appreciated.

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Answer 1

The decrease in flowering is likely due to overcrowded iris plants. When they become dormant in late summer, you can divide them and give them more space.

Leaf spot is a common iris fungal disease. Applying fungicides is best done in the spring on new foliage. To reduce the spread of the disease, remove the foliage with spots as well as the dead, brown foliage.

These articles should help:

https://www.ksre.k-state.edu/news/stories/2023/03/horticulture-iris-leaf-spot.html

https://www.gardeningknowhow.com/ornamental/bulbs/iris/dividing-transplanting-iris.htm

https://ipm.missouri.edu/MEG/2017/8/Divide_and_conquer_Iris_in_August/