They were all doing outstanding, until we installed weed cloth and rock for mulch. (Don't blame me, my husband had to have the rock).

Since then, one by one, the African Iris are rotting at the level of the rock.

The upper leaves look great and healthy, but there is a rainbow shaped streak of yellow and brown rot just above the base of the plant. One good strong tug and up the whole leaves come off.

Is it possible that the rocks are just too deep ? Is there any point in trying to leave the other Iris that appear to be doing well in place ? I've done some research and it seems that if there is a disease I should probably pull it all out. I don't see any bugs when I'm at eye level with the plants as I pull out the dead leaves. Should I be pulling the rizomes out as well as the leaves ? I had been leaving them in place hoping some healthy leaves might shoot up to replace what had been lost.

Thank you for any wisdom you care to share with me.