I have several peonie plants about 3 years old. Do you have any suggestions for succesfully transplanting them to a new home> We have good mulch soil. When is the best time to move them and do I fertlize hole before planting. I live in Astoria Oregon Thank You for your attention to this matter.
Clatsop County Oregon peonies
Thanks for your peony question. It's just about the ideal time! The fall is the best time, because shrubs are beginning to go dormant, and aren't putting on new foliage, nor creating buds for flowers. Here is a link to and Iowa Extension article on peonies specifically. Note, though, that Iowa's winters come earlier than ours, so they recommend September. In Oregon, we say "fall" and that can extend into October. Here's a short article about transplanting shrubs and trees, generally.
As to adding fertilizer, since the plant will not be photosynthesizing through the winter (since it will have dropped its leaves), it needs little if any fertilizer, per se. However, as the Oregon article notes, adding organic material (compost) helps improve the texture of any soil, and, over the winter, microbes in the soil will be breaking down the organic matter, making it available to the plants in the spring.
Don't add time release fertilizer, because it will just get washed through the soil over the winter, and there won't be any nutrient value left by spring. (Soluble fertilizers are pretty unhelpful outside for the same reason.)
Hope this is helpful. Good luck!