We had a bermuda grass lawn when we were in Texas. It was fun stuff trying to keep it out of the garden (which we put in a corner of the back yard - where we tilled in a section of the grass...)

Here is a link that might be useful: Tales of a Transplanted Gardener

I've got runners going 3 foot across the top of the weed barrier w/o rooting .......

If I were you, I'd go after the bermuda grass with a vengeance. It's extremely aggressive and very difficult to eradicate. I read something from either the Colorado or Utah extension service that said it can grow through concrete.

From what I understand, you need to hit it with glyphosate repeatedly to kill it. Either that or water it well when it's going to be hot and sunny for a while and cover it with clear plastic to cook it.

I've identified three main areas, they're still 4 or 5 feet in diameter where it's the dominant grass. I sprayed them this morning, and and I'll do it again in a few weeks. I need to better identify it when its mingled with the other grasses.