Beginner Gardening: Please Help: Plants dying and I don't know why, 1 by danludwig

danludwig wrote:
Yes, the soil is mostly clay. As far as watering, I was following the "inch a week" guideline, except for the one week I mentioned when I went to TN and CO. As you can see in the photo, the lawn has been tilled up. I will be sowing new grass seed there this month. After that is done, I was going to mix in a couple bales of peat moss with some humus & manure to raise the flower beds up to the capstones in the retaining wall (also in photo). Would this alleviate any of the clay & drainage issues? How deep do gaillardia and sky pencil roots grow?

This is the second dying sky pencil. You can see a healthy one in the background. The first one was bare so I threw it away. I can post a photo of the dying gaillardia after everything dries up (it's raining right now).

As far as root rot, what should I look for?

Can anyone else answer the question about grub killer getting through mulch? I know it can penetrate thatch in a lawn, but what about wood mulch (about 1/2 inch thich)?