This Spring I planted 3 Leather Leaf Mahonia plants (30 inches tall) in a shaded area (new organic bed) on the North side of my home. One of these plants is all but dead. The leaves on all the upper branches have turned brown and the stems are brittle (one snapped off when I tried to bend it). Only one low branch is still green.
I have given up on that plant (is there any hope?) but a second plant now has one upper branch with the same symptoms.

What can I do to save these plants?

I have a 7 yr old leather leaf mahonia that took a dive one year when I went on summer vacation. There was a little bit of green left on the plant and I thought it was a gonner. But, the plant came back...very slowly. So, don't give up.

Are they getting enough water? And, did the browning seem to happen all of a sudden or gradually since the time of planting?

I suspect that after the heavy rains in June, I allowed these plants to get too dry. I have planted the three Mahonias near a group of four Texas Sage plants and I am now realizing that the water needs of these neighboring plants are quite different. Should I consider moving one or the other group in the Fall?

I am not familiar with the Texas Sage. I have some Mexican Sage. I wonder if it is the same plant...bushy grey branches and purple flower spikes? Too much water makes the sage's branches brittle. Whereas, the mahonias don't seem to mind heavy rains or overwatering. I have my sage planted in a raised bed with compost and sandy loam mixed into the clay soil.

I would consider moving one or the other. If that area receives less water then I would leave the sage there. However, the sage needs some sun to bloom. So, if there is no sun, I would move the sage and step-up the watering program for the mahonias.

Garrett Juice foliar spraying would be a very good idea:
http://www.dirtdoctor.com/view_question.php?id=157

Texas Sage requires very little water and lots of sun. I would suggest you seperate the two.

http://www.noble.org/imagegallery/Forbh ... sSage.html