Sap oozing from the trunk of plum Q. Last week I noticed sap bubbles 6 to 8 inches off the ground on the trunk of my year old Santa Rosa plum. I removed the bubbles and reapplied the whitewash. I checked again today and they are back. I’ve had plums before and the boars always win. I had hoped the Santa Rosa would do better. What can I do to save this tree? A. Bubbles on plum don’t necessarily mean borers. They can do this with high temperatures. If you don’t see any other evidence of borers like bark coming off especially on the south or west sides then I would leave it alone. Repainting is fine. Try to keep as much shade on the trunk as you can from the canopy or even lean a board on that side of the trunk to shade it if you care to. If there is chicken wire around it for rabbit protection you could wrap something around the chicken wire for some shad on the trunk. I don’t know of any difference between plums in borer resistance so I don’t think that would make any difference. But for now just get some shade on it.