Apparently during Church’s time, not much was known about native oaks and their inability to tolerate summer water. The damage that you can see in these images is the result of placing the trees in the midst of heavily watered lawns, which are still the dominant design element in this garden. Although some remedial work was done to protect the oaks after they began to fail, the ground under them had been covered with a most undesirable (and now ubiquitous) mulch of river cobble.

We now know that soil needs to breathe, and those cobbles that seem to have multiplied throughout California under the misapprehension that they are “natural” need to be returned to the rivers from which they came. There is no sense in placing river cobbles under oaks. Shoot them if they move! Instead try mulch, native grasses such as festuca Californica, and if you wish, large boulders. Better yet, leave them as you found them. If we accomplished nothing else here of lasting worth, we are proudly responsible for the removal of the cobbles.