I believe I have a black mulberry tree in San Diego CA but all the mulberries seem to die they seem to start growing but the die.
The tree is green and looks healthy. We just rented this house and landlord says they got many berries from tree, not sure if it's birds or what need help. Also does it help if I keep the height down and if so when should I prune it down?
Certified GKH Gardening Expert
This is more than likely a combination of issues. A fungal problem will cause berry rot, and loss of fruit. For this I recommend wettable sulfur and dolomitic lime. These two will work together to kill off anything in the soil, as well as provide sulfur for fruiting and dolomitic lime to keep the pH balanced while this is happening.
Next I would recommend fertilizing with a fruit tree fertilizer, or high phosphorus and potassium feed at least once per year.
These will help restore your tree to a properly fruiting state.