Ike wrote:
My neighbor and I have a problem. We have a common cinder block wall
between our yards. We also have a cinder block wall that runs along an
alley, perpendicular to the common wall. Both walls are about 5' high.
The alley wall is pulling away from the common wall. It has bowed out
by 2" at the top of the wall.

I beleive this is due to the Mexican Palm he planted back in the back
corner of his yard. He planted it 2' from each wall. When it was
small, no big deal. But now it is 20' tall with a 30" base and is less
than 6" from the wall. But it is not directly touching the back wall
so neither of us know for sure if the palm is the problem. He is
willing to have the palm removed.

Is there some way to push or pull the back wall up against the common
wall like it was when new? I was thinking a 2" wide by 3' long steel
C-channel as a brace on the ooutside back wall. Drill holes in it
every 8". Then drill deep holes in the cinder blocks and screw some
tapcon cement bolts in to see if we can pull the wall back so that it
once again is touching the common wall. But I have never tried this
before and wonder if the cinder blocks can take the stress. They may
be too weak and brittle.

Any other brilliant ideas?

In a fight 'twixt concrete and a tree, the tree will always win.

Remember how the Ents tore down the wall at Isengard? They simply inserted
their roots into minuscule cracks and grew them. The giant stone wall fell
so fast not even a black wizard could stop it!

You MIGHT be able to salvage things by having a ditch-witch sever the roots
between the tree and the wall. Dig a trench 6" wide and three/four feet
deep.

Fill the trench with concrete.