Peony disease identification help


Dear fellow garden masters,

As a novice gardener, I’m frustrated in deciding to keep my beloved Itoh peonies live or not. They are planted this spring, mid May 2020, were healthy when planting, but within a week, one (the top row of the attached image) showing signs of disease on its leaves, the symptom began similar to the bottom row of the attached image. Up to today, all its leaves are infected by the disease, and was weakened enough that it also caught powdery mildew and black spot during the wet summer of this year. I’m confused about the disease, as some of my neighbor said it’s rust, others said it’s virus. I’m worried about the latter, as the only way to deal with virus is to completely destroy the plant. The disease does seem spreading, as the bottom row of the attached image is the neighboring peony.

If it can be saved, then I’d like to transplant it to a better location, but I’m worrying about spreading the disease: shall I cut off all the leaves, and wash the root soil free when transplanting?

Here are some info:
my zone: 5b, Barrie ON
planting location: full sun (about 7 hours of direct sunlight); well ventilated (plants are 3 feet apart and the bigger/heavily disease one is about 2 feet wide, the other is only 1 foot wide), quite windy location.
soil: loam-sandy, very well drained; PH neutral (around 7)
heavily disease peony: Scrumdiddlyumptious Itoh peony, 2 by 2 feet in size; top row of the image
lightly disease peony: Bartzella Itoh peony, 1 by 1 feet in size; bottom row of the image

Thanks for your advice in advance,


Your photos are not quite clear enough to make a definitive diagnosis so I am attaching a similar question that was answered recently by the Toronto Master Gardeners in the hopes that this might help you, see below.

Peony – Toronto Master Gardeners

I’m also attaching a link to the American Peony Society’s Disease & Pest webpage which has super pictures of ailing plants so that you can compare these to your actual plants – again see below.

Peony Diseases and Pests | American Peony Society

There are a number of factors to be considered when determining what the plant problem is, such as:

  1. Are the affected leaves old growth or new growth?
  2. Is there a nutrient deficiency or over fertilization?
  3. Are the plants over or under watered?
  4. What is the soil pH?
  5. Is soil drainage good or poor?
  6. Is there enough sunlight?
  7. Could road salt buildup or fertilizer salt buildup be an issue?

Perusing the above links and answering the above questions may just steer you in the right direction, which will allow you to take a course of action in order to save and maintain these lovely specimens.

Good luck.