Bad weeds - overseed or kill everything?
I purchased a house that sat on the market for a while and the yard is overrun by weeds. I'd say its 90% weeds and 10% Bermuda. I live in San Antonio, Texas in the Stone Oak area. I basically live on a big rock and there is very little natural dirt here. The dirt in all the yards was hauled in during construction, so it's not very deep. You can only dig about 6 inches before you start hitting rock. That makes it hard for most grass to develop a root system. Also, we're usually on water restrictions because we don't get much rain here. During the summer, we're usually only able to water once a week. That's a challenge for a couple reasons. First, our yard is sloped and not flat, so the water runs off if you water too long. Also, since the dirt isn't very deep, it's also not advantageous to water for very long since it gets saturated fast. Ideally, I'd rather water for a short time every other day or so. I also have bad erosion for what it's worth.
My question is, considering how bad the weeds are, should I kill everything and start over? My other option is to haul in some dirt and seed some new Bermuda. I tried seeding last year without hauling in new dirt and the seed didn't germinate. I think the dirt is too hard and I didn't plant it deep enough. I know you just need to rake it in, but for whatever reason it didn't work. I didn't put down a pre-emergent this year so that wouldn't cause it not to germinate. I know it would be a lot of work to kill everything and haul it off to start over, so I'd rather try seeding first. But, if you guys recommend starting over from scratch, what do you recommend planting? Should I plant Bermuda again? If so, what strand for my area? I had St. Augustine in Dallas and it did really well, but got lots of rain there. I don't want anything that will require too much water here because of the restrictions. It would be nice to have something that would grow in the shade too. I've spent a lot of time, effort, and energy in my yard and nothing has worked. If it weren't so expensive, I'd kill it all and put in artificial turf! If anyone is able to offer any insight it would be greatly appreciated.