I doubt the Bermuda did it. Apricots don't do well in SoCal -- that's where you are. Right?

The Bermuda was covered for 8 weeks. We have not yet removed the plastic because I'm not yet sure if we should add topsoil or remove all of the dead bermuda first. I looked under the plastic, and all of the bermuda and weeds are white and dead.

Best way--and hardest work--is to just keep pulling the bermuda grass out. Water well, then start pulling when the soil firms and water has soaked in a bit. There are a number of herbicides that target grasses, however few of them have labels for flower beds. In some cases, the grass herbicides will also have some activity against certain broadleaves, so if you go off-label and just try something, you might get a few of your flowers as well. You might look at Preen in a small area as it is recommended for grasses, but don't know what it may do to the plants you want.

Bermuda will require multiple treatments of RU to effectively control it. Using more R/U or for that matter any other herbicide above the label rate actually makes the herbicide less effective. "Burn down" may occur where the vegetation is so severely damaged so quickly that the product is not translocated to the roots. A sod cutter is a great way to increase the density of your Bermuda turf when it grows back and insure that you are removing as much of your precious topsoil and organic matter as is physically possible. A sod cutter, unless it is set very deeply (which makes the rolls extremely heavy) simply root prunes the Bermuda. Where there may have been one plant before ten new individual plants may return. One of the best herbicides to use is a product containing fusilade. It is a selective grassy herbicide and is considered an 'over the top' spray safe for use in the landscape to control several types of grass. The problem it is slow-takes about two weeks to see visible results. R/U very quickly becomes inactivated once it hits soil. I would recommend, a treatment with R/U, till in two weeks, wait two weeks until it shows regrowth and respray and then wait another two weeks to see if it reappears before actually planting. This way not only are your preserving the existing OM in your soil but adding to it with the Bermuda residue. Also, include a sticker in your spray mix. It basically increases the effectiveness of any herbicide by at least 50%.