The yard is covered with brown-spotted yellow leaves from our three mulberry trees. Are the trees diseased?
Mulberry Dropping Leaves With Brown Spots
Certified GKH Gardening Expert
This is a Leaf Spot fungus. It generally will not harm a tree but you should try to control it with
a fungicide treatment.
Clean up any dropped leaves on the ground around the tree and dispose of.
Here is a link with more information.