Q.Potted Lemon Tree Leaking Sap?
This is a young lemon tree. Issue started with leaf curl. Then bloomed and dropped all budding fruit. I sprayed with copper sulfate and had a lot of leaf fall. Then these sap beads appeared and are progressively getting worse. What is going on?
Certified GKH Gardening Expert
Sap will leak in the case of fungal or bacterial disease, usually bacterial, and insects problems.
Because of how the damage appears, I would say that this is likely bacterial. A single use of fungicide will not be enough to kill off the infection, so multiple treatments will be necessary. Depending on the infection, it may be very difficult to rid.
To prevent future infection, once you do manage to kill off the existing infection, will require keeping the soil from staying moist for too long. With that style of container, rain will build up in the drain pan. You will need to make sure to dump off all extra water that ever accumulates in the attached drip pan, or simply put it into a container with plenty of drain holes to allow water to leave freely.
Make sure that the soil dries down to at least 3 or 4 inches between watering.
Here is an article that will help you to care for a lemon in container: