I've seen caeruleas down there (burbank / van nuys) *completely* cover those tall skinny juniper-looking trees... My sis had 10 - 15 in her back yard along the fence.. Couldn't even tell what kind of trees they were. The bushes along the back of the pool? (Where the helicopters dip during the fires...) Covered. Neighbor's fence? I think there was one under there... The vines were as thick as my wrist in some spots- Looked more like 'tree wood' than 'vine'. I don't think it's the parent vine that's covering the whole thing (in your yard or hers) as little 'volunteers' were coming up all over the place. Don't know if they were suckers or from seed- As hers had fruit all over it as well, some seeds had to fall & sprout. I'd imagine they might be like the blackberries up here- Give them space, eventually they'll fill it. If it has no natural controls (butterfly larvae, disease, those weird bugs who eat the seeds) & manages to avoid attacks from the weed-eater & lawnmower I don't think it has a limiting factor.

What can happen is that if young trees get engulfed with vines, they may not be able to leaf-out as well and the leaves that do come out may become shaded by the leaves of the vine. This may result in stunting. Eventually, with not enough canopy, the tree will decline and eventually die. More mature trees with canopies well above the vines, seem to fair better but may eventually suffer if the vines reach up that high. You are correct about volunteers getting out there and clearing trees of invasive vines. That happens here in my city within the Fairmount Park system, but it is a long and arduous process - particularly when care is taken to attempt to eradicate the point sources of the vine so it doesn't resprout and begin again. I recall some honeysuckle engulfing shrubs in one of the creek tributary portions of the park system. The honeysuckle itself was later engulfed with sweet autumn clematis by late summer/early fall, believe it or not. The poor shrubs (I think some may be viburnums) just couldn't compete with 2 invasive vines covering them. Fortunately someone got in there and cleared the shrubs.

Why not kill the vine with kindness? Fill jars with dilute Roundup solution (3 parts water, I part Roundup), place ends of vines in the jars through holes in the lids and seal the jars by twisting the jar, not the lid. The jars can be hidden by shrubs or other vegetation. The vines will gladly take up the Roundup/water solution and be grateful for the additional water. Top off the solution in the jars as needed with additional solution as the vines take in the water and transport the roundup into their roots. Next year, the vines will be very unhealthy if they even survive the winter. Repeat the second year if necessary. All the roots are probably interconnected, so all parts of the vine in your yard and the neighborâÂÂs yard will eventually die. Commiserate with the neighbors when they express sadness over the unexplained death of their beloved vine.

I’m not sure where you live but it looks and sounds like sumac. I found this webpage about it and it mentions using Garlon. https://pleasantvalleyconservancy.org/sumac.html