peony foliage damage
we had three peonies show foliage damage in a new bed. most of the peonies were planted in the fall of 2018. the soil is clayish. 28 peonies look good. Four had reduced growth. nine did not emerge yet (dead?). could this had been a moisture problem? we did have a contractor spray weeds in the beds on site but I did not notice any weeds dead or alive in the peony bed. could this have been the foliage problem?
Howard County Maryland
These symptoms -- the yellowing and distorted growth -- are indicative of herbicide injury. https://extension.umd.edu/hgic/topics/herbicide-damage
Given time, some plants eventually grow out of the symptoms of herbicide damage. There is nothing you can do at this point but wait and hope for the best. The plants need green foliage for photosynthesis and putting energy down into their root system so that they can survive the next winter.
If the soil in this area remained very wet over the winter, it is likely that some of your peony bulbs rotted. Most bulb plants will not tolerate poor drainage. You will have to replant the ones that didn't make it. https://extension.umd.edu/hgic/topics/bulbs