John, first off, congrats on knowing to remove the mulch volcanoes! BTW, was this composted material or more or less "raw" bark and/or chips? Not that it makes that much difference-nothing should be piled up against tree trunks, and oaks generally are very intolerant to that.

As to species selection, I'm afraid the list would and could get very long. You're set on native species-bravo-so why not visit native plants gardens, etc. and begin to make a mental list of what you like, don't like, etc. since you're working in at least partial shade, that will inform your search more than anything else, I should think. Good luck, and as one more comment, I and everyone else here champion the use of native plants, but every non-native isn't a problem. It may be that some of what you've got there could work with the natives you bring in. Just saying....

+oM

PS....Chicago botanical Garden has-I believe-made quite extensive inroads into exploring, developing, and using native species. They alone could be a huge resource for you.

I believe it was mostly composted material and then topped off with uncomposted wood chips. I am sure I can find a useful place to remove it to since our plans seem never ending. It will be a big project as we will also be transplanting whatever it is they had planted.

As far as proximity to the oaks goes, do we need any sort of buffer zone around the trunks where nothing should be planted? Or is leveling out the tree volcanoes enough?

I will check out the Botanical Gardens. We are also right down the street from Cantigny and I know they have a number of gardens. And St James Farm and Forest Preserve is right across the street. It might make sense to see what sort of things they are planting since they are in the middle of renewing a huge section of forest.

My desire to use native plants also comes from the desire to not need to water as much since the previous owners have the outside spigots hooked up to the treated water. I changed one of them over and added a number of rain barrels, but still would rather have plants growing that will do well with as little help from myself.

I noticed yesterday, before the snow storm came this morning, that there is quite a bit of moss growing around and about the front yard. A few different types - I will have to look them up once the snow melts. I think even these alone would be quite beautiful if I can figure out a way to help that spread out and about a little faster.

Agreed-moss is beautiful. I think once you've removed the excess material, you'll be good. The only caveat I'm aware of-and this is for working under trees generally-is to try not to tear the root system up any more than necessary. I'm sure you know that already. There's no special oak aspect to that. Now out in Cali, and I suppose, up into S. Oregon, they have oak species adapted to that climate's dry summer. So when people plant garden stuff under those types of oaks and then go on to water that plant material all summer, phytophthera root rots and all manner of problems set in. You won't have that issue where you are, your native oak species being adapted to even precipitation throughout the year.

+oM