[Arid_gardener] Question from Home-Hort WWW page

[binaz at wbhsi.com]

Bee
85248
binaz at wbhsi.com

My leaves on my rose bushes have turned yellow and then they brown around the edges...the brown is crispy.  The leaves have dropped from the bottom and have worked up the bush..these conditions have spread to the rest of my roses...right on down the row!  The first bush to be affected is almost bare of leaves.  I tried to shake a "bug"(mite?) from the leaves onto white paper-nothing appeared and there are no cobwebs.  The probe shows about 18" of moiste soil.  The bushes are in dappled shade due to a 50% shade cloth. What is the problem and how do I fix it?  Thank you!