While I was recently helping my mother prepare her garden for the spring, I discovered that the leak on her porch was not actually coming from the overhang above the door, but rather from a branch of her grapevine.
Examining closely, it looks like one part of the grapevine (which was planted two summers ago), is leaking what looks like water from an end that has a clean cut (it was probably cut a while ago).
In addition to the clear liquid, there is a slimy (not frothy) white substance from the cut end, down to the point where the liquid drips off the vine, which looks a lot like mucus or something, but is not thick or sticky because it wipes off quite easily (but it seems to build back up quickly).
The drip has been going (slowly) for a week or two but got intense recently and is of sufficient quantity that there is a fair sized puddle on the shelf under it.
I took some pictures. The white stuff is definitely not foamy like the stuff that some bugs leave on plants; it is slimy. The fluid is definitely coming out of the end (#) but that is not the only end that is cut, there are a few others (some on the same branch, and one pretty close that is even facing downwards) which are not leaking. It’s not clear if the white stuff is coming out of the branch or just building up on it (like mold that builds up due to moisture).
In addition to the unexpected white goo, she is worried about the sheer volume of liquid coming out. As you can see, there is a substantial amount coming out (the 1L mason jar is nearly half full after ~16 hours). She said she tasted the clear liquid (actually it is slightly cloudy), and it tasted like water. She is worried that it is essentially leaking the liquid (read bleeding) instead of actually making use of it to grow and live.
I tried Googling this but could find nothing anything useful. The closest pages discuss leakage of general water and sap, and there is a page that shows the same problem with a white goo, but without a resolution.
Possible related information includes that there were little beetles on the grapevine last year (though we have not seen any—yet—this year, and there was no white goo last year). Also, the weather has been pretty cold here and only just warmed up today (May 1), and has cycled between high and low temperatures several times in the past few months.
Possible Actions and Concerns
There are three obvious moves:
Do nothing. This is natural, but it would allow the plant to keep leaking which could be a problem.
Cap the leaking end. This makes sense, but if it is an infection or something, it would trap it inside the plant.
Cut the whole sub-branch. This also seems logical, but would be excessive if it is not a problem.
Basically, the action to take depends on a diagnosis on whether or not the excessive leaking and white slime is bad.
The leaking got intense on Thursday and continued unabated throughout the weekend. By Tuesday it had stopped and the white slime had dried up.
Does anyone know what this is, whether it is/was a problem, and how to fix it/prevent it in the future?