Wednesday, May 28, 2014

2014 Intersectional Peony Fungal Diseases

Intersectional Peony 'Misaka'
with Phytophthora? Fungal Disease

This year I noticed the same three intersectional peonies had the same fungal diseases they did last year. I was wondering if there was anything I could do to prevent it next year or if I need to get rid of the entire plant. None of my other intersectional peonies have any diseases to speak of. However these 3 specimens were apparently sold to me with the diseases, unfortunately. The intersectional peony pictured above, Peony 'Misaka', I purchased as a potted plant from a local nursery, and it did seem a little suspect when I bought it. I'm wondering if it has Phytophthora blight because of the curled, deformed leaves. Plus I've seen plenty of Botrytis blight on my herbaceous peonies before, and this seems to be a little different. I guess I know better now than to buy anything that seems a little iffy. However the two intersectional peonies pictured below were both purchased as roots from two different reputable growers. I had never seen any incidence of Peony Blotch in my garden until I got these two intersectional peonies with the disease, Peony 'Layfayette Escadrille' and Peony 'Scarlet Heaven'. That is interesting because both of those 2 intersectionals are red in color. I wonder if they are somehow related and more susceptible to the Peony Blotch fungus.

Intersectional Peony 'Scarlet Heaven'
with Peony Blotch Fungal Disease

Intersectional Peony 'Lafayette Escadrille'
with Peony Blotch Fungal Disease

When researching these diseases on Google, I found this awesome page on Peony Problems on the Missouri Botanical Garden web site. It seems like the only thing I can try to get rid of these fungal diseases is to make sure to cut these peonies all the way back to the ground in the fall. I will try that and hope it works, since I usually don't cut my intersectional peonies all the way back. I try to cut them back only to their lowest surviving bud, which usually keeps a bit of the stem there. I hope it does work, since the MOBOT web page seems to suggest removing and discarding the plant and its soil entirely as the only other alternative. I hope it doesn't come to that... :-(


  1. Hi Adriana,

    I've been a long time follower of your blog, but this is my first time commenting and I hope it helps. I am not sure if this is what you are experiencing, but I was recently looking through some Canadian online catalogues and found a description of Lafayette Escadrille that said that it is prone to brown spots in hot summers. This is apparently a genetic characteristic of the plant. The description can be found on this page:

    My Scarlet Heaven does tend to go a little brown in some part of the leaves, but nothing as pronounced as your photos. This is very odd indeed as I find my intersectionals to be the most disease resistant of all my peonies.

    1. Nick,

      Thank you so much for that link. That is interesting information. I'm wondering if genes that are needed for the red colored blooms make the plant more susceptible to these brown spots.

      Yes, my intersectional peonies also seem to be the most disease resistant peonies in my garden. That's why I found it odd that these 3 had diseases while all the rest have very clean and healthy foliage.

      Thanks again,