Some folks say anything plant or aminal, some folks don't put in any animal matter (meat, fish, bones, cheese, animal fat, animal feces, etc.). Read the FAQ and do a search at the Soil, Compost and Mulch forum for more input.

Here is a link that might be useful: Composting at Home - OSU Fact Sheet

Thanks, Diane, for your response and the links. I'm pretty much on track with the advice they gave. I'm still wondering about being told not to use peony stems. Does that ring a bell with you at all? I also wonder if the black spots that are sometimes on peony leaves the same as the BS that affects roses. Any thoughts from anyone?

This is a quite late reply but the black spots you see on Peonies are not the same thing as Black Spot on Roses. You can compost those Peonies just as you can compost anything else. There is a lot of research out there that indicates that composting diseased plant tissue can result in antibodies in your soil to those diseases that will help your plants better resist infection. I do not allow any plant material that grows on my property to leave, if it is not put right back into the soil it grew from it is composted.

Can you tell us where to get more info on antibodies in the soil, kimmsr? I'd love to try to use the information to strengthen my roses against several diseases.

The link below will take you to one of many articles about this subject. I had a link to an study done by Dr. Leon Hoitink but Ohio State must have taken that one off.

Here is a link that might be useful: About soil borne disease suppression

kimmsr, that is a great link, thank you. Not only did I learn but actually got sources for some cool microbes!