I had a 15 year old, non-bearing, Mulberry tree die in 3 months. It lost its leaves in December (Pheonix, AZ) and never came back. It looks like it was dipped in a vat of liquid nitrogen. I dug it up today and the roots are black, rotten and stinky. It was watered every 4-5 weeks in the winter and every 2 weeks in the summer via flood irrigation. Fertilized with cow manure yearly (we own the cow). Any ideas what this disease is? I've burned the tree and root ball and left the hole open to air out, but am concerned about my other trees. My other Mulberry, about 50 feet away has markedly small leaves this year.
Certified GKH Gardening Expert
The tree has definitely suffered from root rot as a result of overwatering, especially during the winter months. These trees do not need to be watered so much during their winter dormancy or you will run the risk of rotting the root system, which I think is the case here.