Kudzu:

Control of vegetative growth is best achieved by pruning in late summer, after terminal buds have set. You could prune now, but the likely result would be multiple new shoots at the pruning site over the course of the growing season. Late summer pruning may not stop the upward growth of the trunk, but it will certainly slow it.

If the trunk beneath is quince, the vigorous shoot above it is certainly quince also. It is a little unusual to hear of a tree grafted in this particular fashion, but there is certainly nothing wrong with it. Did you place the grafts yourself?

You might also consider heading back the vertical shoots from your fruiting branches at the same time, to encourage their development as fruiting wood, although tying them down should slow their growth.

Don Yellman, Great Falls, VA

Jellyman-
Thanks for the good advice. Here is a photo of the tree I took a week ago (before it burst into bloom). If you look closely at the point where the top white tag is, there is a vertical shoot starting almost exactly where the uppermost tag is attached to the trunk; that's the one I'll prune in the fall. There is also another vertical shoot just to the right of that one which I have since bent horizontal. If you have any more observations after seeing the photo, I'd welcome them. In any case, thanks.

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Or you could leave the central branch and graft another variety higher up to create a fourth tier.

Tell us the story of those imprisoned rocks.

murky-
Thanks...not a bad idea. As for the imprisoned rocks, well, those are called gabion baskets, which are typically used for erosion control and for retaining walls. I live in a kind of modern, funky house and the architect decided to use gabions as a cheap way of producing freestanding stone walls. Here's another picture to give you a better idea:

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People either love then or hate them. I like them because they're great for growing things on.

I totally love them. That's a very nice place. And I just wasted money on a cedar fence and my girlfriend is planning to build a trellis in front of it :(

Of course, we probably have different ideas of what "cheap" means.

Is that an indoor tennis court, or an airplain hanger to the left of the picture :) ?

murky-
To the left...that's my favorite room...the garage!