What are the ties for? Do you mean cavity wall ties? Why would there be a cacity? Do you mean anything more substantial? What's the other end attached to, and unless it's two walls surrounding an embankment, there's not likely to be much call for them. It's very rare for a retaining wall to be _designed_ to need ties, rather than to have them added to restrain a slumping embankment.
Big garden if it gets to that size. You'd have to be Steve "Lord of the Manor" Firth.