Eventually, we got the basic trench all the way to the back of the yard, up against the wall that we built last year.
Now we turn and start digging along the wall to the other side of the tree stump.
And then we turn and dig towards the stump itself.
The top layer of dirt is what we brought in last year. Below that is the mix of leaves and dirt that we dug up, and below that is the layer that the roots grow thru. The roots have a relatively narrow layer of dirt to grow in, maybe 8 inches deep. Below that is a layer of rock. Crumbly rock, but rock. So if we dig into the 8 inches of dirt just above the underlying rock layer, we find the tree roots.
Removing the roots -- using an axe and a chainsaw as necessary -- gives us a thin layer of dirt to scrape off.
And shoveling that dirt out of the trench (and into the growing dirt pile by the street) exposes a layer of rock that we will need the jackhammer to break up and remove.
As we dug the dirt up and separated out the rocks, we added leaves and grass to increase the organic content of the dirt, trying to make it good soil instead of just plain dirt. We got bags of leaves from the neighbors, but now have used all of those up. We stored the leaves at the far end of the trench, but now it is fully exposed, and we see there is also a layer of rock to remove from the other end of the trench.