I recently planted a young California black oak a few weeks ago. I have been noticing the edges of the leaves are slowly turning brown. The leaves are still green in the middle and looks healthy other than the brown. I would really appreciate any feedback on what this might be or how i can fix this problem. Joe Reed northern California
With plants in general this can be mineral salts in irrigation water, excess fertilizer or sucking pest infestations. Look for salt deposits near the brown zones, if nothing there then tiny critters (maybe use a magnifier).