I live in Arizona and have an 11-year-old Tangerine tree which produces a good quantity of fruit each year. However, the past two years the fruit has been very sour. Previously it was fine. Do I need more fertilizer? More water? Any help will be appreciated.
Certified GKH Gardening Expert
This is likely caused by a nutrient imbalance. I would recommend having the soil tested at your local extension service and adjust the soil based on the results.