Oak trees do not like to have their roots compacted or disturbed and they do not like any extra water in the summer. Do not plant within six feet of the trunk of your oak but you could use a mulch in this area. Native wild flowers could work in this area as long as you realize they should not be given extra summer water. You can rake up the fallen acorns before spreading the wild flower seeds but use a light rake that collects the acorns without disturbing the top few inches of the soil. Once the flowers are established don't worry about the acorns falling on to the plants. The wild flowers of your area should be able to handle your summer weather and some acorns. Good luck with your new project as I am sure the wild life in your area already love the oak tree and will also enjoy the wild flowers. Keep growing, Marianne Binetti