This has been helpful, and I'd like to add an additional question. We removed a huge dead maple maybe 10 weeks ago, lots of stump/root grinding. Removed some of the piles of wood chips. Yesterday moved a spirea to the area, adding a few shovels of topsoil, some coffee grounds, and a little worm compost. I think the spirea will do fine. However, I'd like to speed along the wood chips that now make up a huge portion of the top several inches of this area (maybe 5'x8'). If I mix in coffee grounds to the whole area, will that help? I can of course get huge quantities of those for free. Any other ideas? Thanks, all.

Gotcha Dave. Sour is often used to mean acidic, though most folks don't probably realize that when they use the word. But I see what you're saying. For my part, I would never advocate purposely mixing uncomposted woodchips into soil. As a mulch layer over the top-yes, of course. But not mixed in. The other problem with bark or woodchip mulches is their tendency to form a hydrophobic mat. It seems that some of these beneficial fungi which colonize the chip layer, over time, glue the whole thing together with their mycellia. I've already seen it where you can lift an entire tree ring of mulch with one hand like it's all one-piece. The only reasonable method for dealing with this-so far as I'm aware-is to get your three-prong cultivator out and gently work the stuff up. That also freshens its appearance. We use wetting agents to water some of our ornamental plantings in areas where stirring up the mulch isn't feasible, but I wouldn't expect the average homeowner to be purchasing wetting agents! BTW, some folks claim just your general-purpose dish detergent will "work just as well" as the expensive pro stuff. I can tell you from direct experience that's not necessarily so. The big manufacturers of consumer goods like dish detergent vary their recipes as different supplies come and go, or as ingredient prices rise and fall. So you never really know what you're getting. At least with professional wetting agents, they are what they say they are. And it is possible to find relatively low-cost ones, relatively being the operative word there. +oM

You'll get some mushrooms as decay fungi work over the remaining wood. Not a problem in my world, ymmv. The soil will also settle one day as the decay progresses. Ditto to the above-no biggie. Studies in these naturally-occurring assemblages of trees we call forests show that roots of "new" trees very often follow the pathways made by now-dead and gone trees old, now-rotten root systems. So there's no reason to think there's automatically anything suspect about what you've done. I'm pretty sure it'll work out just fine. So, the big guys in the industry have a term for the temporary tying-up of N in the soil matrix as these decay fungi do their work, using N in the process; They call it nitrogen drag, and it is a real phenomenon. But the thing is, let's say your newly-planted tree starts to exhibit chlorosis, a yellowing of what should be green foliage. Well, all one need do in that case is broadcast a little nitrogen fertilizer over the area, which should alleviate the problem. Nothing to get all worked up about, though I've seen that reaction on these pages from time to time. On the city terraces where so much of my tree work has happened over the years, there is not always sufficient lateral space to place anew tree very far from where a big old monster has been taken down. In such cases, we will occasionally see this chlorosis. But again, it is easily rectified, and goes away eventually anyway in most cases. +oM

All true-I've seen the water-repelling tendency of some mulches sometimes. Camp's suggestion to preset the soil is a good one. I'd like to just quickly address one point here: folks often will say or write things that indicate that organic materials, in the process of being broken down by soil microbes, will "rob" that soil of nitrogen. In actuality, no such thing happens. What does happen is that these microbes will temporarily use or tie up that nitrogen in their processes of breaking stuff down. But then you know what these things do? They die, and all that N is re-released back into the soil matrix. So it's really more of a borrowing. Still important to know, but I just wanted to slightly readjust that paradigm. Soil microorganisms are the single most important factor in tree health, beyond such obvious factors as light and moisture. And those fungi that work with tree roots-mycorrhizae-are true workhorses in both our planted environments and in the large thing we call nature. Indispensable.