(Yeesh, not sure I'm attaching this pic right... anyway...)

Do NOT post pictures to a non-binaries newsgroup. Subscribe to
alt.binaries.pictures.gardens and put it there or put it up on a website.

This is a pic of the tree in my new front yard. I'm not sure if
they're visible, but there're some fairly good sized Rhodies on the
other side of this tree, in all the whole thing is about 10 feet
across or so. The front of the house has railroad tie retaining walls
that are beginning to buckle outward, so an upgrade of those too, will
need to be done at a later date. I've always fancied rock walls with
things planted in the cervices, anyway, I was thinking of having some
big rock delivered and building a circular retaining wall, and then a
small one inside and above it, as well. I was wondering if anyone had
any ideas about that, or any other ideas for retaining walls they
might like to share. My husband and I are DIY's, and this seems like
the perfect small project for us, for a couple weekends or so... what
do you think?

As for plants, once the Rhodies are removed to better areas, I was
thinking of Callas and Hellebores in the top ring closest to the
trunk, and then St John's Wort and Vinca in the lower level. I live in
Snohomish, zone 8. I appreciate any thoughts, tips, or wisdom! Thanks!

I'd be interested in seeing the picture to use as a backdrop for your
posting -- something's not quiet meshing in your description. On the one
hand you're talking about 10 feet across, then you're talking about
building rings...?

FWIW, I would not recommend building a retaining wall out of stone. I have
a few of them here -- not fun, not fun at all. From your description, it
sounds like you might find it better to terrace the area a bit instead. I
also noted in your other post that the tree is in the middle of a mound of
dirt -- you start building retaining walls you may damage the root system
either directly or indirectly. Remember that the mound is a fully function
ecosphere of its own -- including the rhodies.

As for moving the Rhodies, be sure to move them to the right habitat --
they're a bit particular and I'm sure they very much like where they are
(acidic soil, kept that way by the tree's droppings, likely a decent amount
of shade, protection from wind, etc.).

It's usually best to try to work WITH the existing scape than making radical
alterations.

Just some food for thought.

James