Mulberries are one of those plants that seem to grow everywhere. They are said to be grown in more countries throughout the world than any other species. The one you have is probably Morus alba Chaparral. It will need little in the way of special attention. While it is very tolerant of both drought and infertile soils, it prefers and will do best in moist fertile soil. So, just keep the root-ball and surrounding area moist until the tree has established itself. Apply a circle of mulch about 6 feet in diameter and about 4 inches deep around the tree, keeping the mulch pulled back at least 6 inches from the trunk. If the tree is in the lawn area, the normal applications of lawn fertilizer should be sufficient. If not, approximately 1 pound of ammonium sulfate (21-0-0) per inch of trunk diameter should be applied.