Good news - no need to dig up landscaping
Whew. The guy who I hired to come and give me an estimate on digging up and replacing some or all of my septic line suggested that I let someone come in with a camera to scope out the tile first to see just what the problem was first before taking drastic action. His business routinely has another company come in esp. for this job, and both came this morning. The cost was going to be between $200 - $300 just for the use of the camera! But, hey, you have to do what you have to do.
Long story short. John says the camera shows the old clay tile is still in good shape with minimal roots for most of the length. No bottoming out of the tile, that is, it's running level and flow is good. Then the camera crew went to the cellar and put the camera through the old cast iron pipe that goes from the bathroom to the tile. Here it found more of an accumulation of "long thread-like" roots. This portion of tile line runs under the garage. Uh-oh. I told him I bet it was the Virginia Creeper growing up the side of the garage! They went ahead and snaked them out. (probably another $200)
So....no need to dig up the edge of the courtyard garden and sunken garden shrubs! Hoo-ray. But - it was suggested I might want to remove the Virginia Creeper. Ugh. I did take it off the one side of the garage when I needed to paint two summers ago and have managed to kill off the roots and new growth there and keep it under control. But it's always so beautiful in the Fall on the side facing the courtyard and creates a green wall in summer. Oh well, all good things come to an end.
The camera was well worth the $300 in my opinion. Plus John was honest enough to bring those guys in and not do $2000 worth of digging and replacing tile and carving up the garden when it wasn't needed. However, he said if I wanted to really do it right I might think of someday replacing the tile line under the garage. That is, close that off and lay it somewhere else.