Maarten Smet wrote:My biggest concern would be compaction of the current soil by adding new soil, suffocating the tree roots as they no longer can get oxygen. I would just add enough cardboard/paper to kill of the grass/moss and just enough wood chips/mulch to keep the cardboard/paper from flying away with the wind.
On sheet mulching--I live just a bit further south than James Landreth, west of Longview, WA, and am just over a year into implementing/learning permaculture in this region. Last May we planted a number of mostly-native shrubs, ground cover, and a few trees, mostly in a nice big yard of lovely green grass. I filled a wheelbarrow with water, soaked cardboard in it, laid it down around the plants--overlapping, and covered with 3-4 inches of grass clippings from lawn mowing. At that time, grass was the most-available mulch. By now the mulch has decomposed. After wind had dropped many small douglas fir branches, our neighbor who has lived in the area for decades told me that after I pull whatever grass or other plants that have grown through or on the mulch layer, to mulch it all with the fir branches/needles and the grass won't come back. So that's what I'm trying.
Around our old fruit trees, we've mulched with bark removed from firewood. I want to cover the grass with cardboard and mulch out farther, to the driplines or beyond, and plant companion/support/layers of plants under and around these trees. thank you all for the lists of plants. Hannah