We live in Los Gatos (near San Jose) California, with a mature 20+ year-old Lisbon lemon tree - grew in a barrel for 15 years, then transplanted into a bed about 7 years ago, after which it grew to about 7' tall. It has been a good producer and looked very healthy until about a month ago, when it started on a steep decline with all leaves curling, some turning yellow, and the whole tree just looking very sick and sad. There is no sign of pests on any of the leaves. When they are uncurled, they look clean and complete. We have micro-irrigation, so that has been steady for a number of years. Other shrubs in the same bed are healthy as ever. Is our lovely tree done for, and if so from what likely cause?
