Mature bush died & now another bush is looking sad

Check for signs of insect, webs,scale etc?

Maybe sprinkle some Osmocote or other ER fertilizer all around the area. I assume you've checked for insects, fungus and other things that kill bushes and trees. Good luck!

Stones are very bad for shrubbery. They heat up in the summer making the soil hotter than it should be. This heat dries out the soil. The stones also block water from getting into the ground.

I would have a soil test done. There may be some nutrients lacking in the soil. The bush in the left front has a lot of pale green leaves meaning it needs iron unless the leaves are suppose to be yellowish. Also shrubs need a long slow soak, not just a short watering. Are you doing that? If this is a newer house, sometimes workmen leave chunks of cement and other debris covered by dirt in a garden that will affect plant growth. There are many reasons...sorry I can't be specific.

Two things killed the plants on the side of my mothers house. One of them was the hot water heater went out and the hot water drain was overflowing into the bed and hot water kills plants the other thing was salt don’t let any salty mixtures get thrown into the bushes or around the bushes salt and hot water will both kill your plant, so investigate and good luck

Are these bushes on the West or South side of your house? If so, between the heat from the brick of the house and from the rocks, they were baking. I live in southern OK and it gets HOT and dry here in the summer. I know most of TX is even hotter. Others have made great observations and suggestions to follow. Hope you can save the second bush.

The rocks are fine. Yes to soil test, too. Slow deep water, wash off foliage during dry spells. Or r and r with something fun and colorful.

Some things are dying because of a boring insect gets inside. Another is thick cobwebby type stuff that hides in the branches. In my area a lot of things are dying. It started in Tennasee in the mountains and made it to Ohio. It attacks certain trees and shrubs. The area has been asked not to cut down trees and take to other areas. I hope this is not your problem.

It looks very close to your foundation and so as a result it may be too dry, especially if you have over-hanging eaves.

Im wondering if its too much lime ! Its close to a human built wall so run off cement can poison the roots eventually and like another person mentioned your stones will get hot and also the minerals from them may be overload. Try moving some stones for a few weeks and put a couple of buckets of horse or pig pooh around the root area water every day so that the pooh gets chance to filter down.you can then put some ( white) liner or even an old bit of cotton sheet on ground touching stalk and then put your stones back.that will help with the "hot stone" problem. Good luck.

It's probably not bugs or disease. Those are plant specific. I think it's the rocks. Rocks/stones don't benefit your plants or soil in anyway. The soil is most likely alkaline, because of the rocks and this has prevented the plants from rejuvenating.