Is trumpet vine hardy in Denver? Around here trumpet vine's natural habitat is twining through trees on the edge of fields. How is your neighbor going to feel when the vine grows through and over their tree and runs riot on the fence. You might want to ask them first. You could also grow it up a tall pole. That way by pruning you could keep it controled. I've seen it grown up poles and kept in a tree form. The most floriferous plants in my area get a lot of sun. Until the electric company came through a month ago there were some really spectacular vines growing on power poles. I hated to see them cut down, but by next year they'll be back.

They flower best in full sun, but probably don't need more than six hours a day. I'm trying to train three to a fence, and they're growing so long I have to keep winding them back and forth. The main vines are producing side-shoots that are ending up crawling on the ground, and flowering there. I'm letting it grow fairly wild this first year so they can grow strong roots, but in the future I'm going to lop them off about 5' tall, with as many branches as possible below that height. (If you pinch them back, they branch freely.)

I used to own an old house with a well-established and trained trumpet vine. The previous owners had let it sucker freely to form a dense hedge with multiple trunks (30 - 50) along a fence. Additional suckers were kept under control by mowing on both sides of the fence, allowing the 'hedge' only only a 24"-wide bed. A branchy crown was left at the top of the fence. Every year it flowered profusely along the top of the hedge, and the whippy new flowering (spring/ summer) growth was trimmed back to the 'crown' every fall. That system worked well to keep it under control and in constant bloom, and I intend to try to duplicate that here. You may be able to do the same thing, so long as the neighbor doesn't mind mowing his side - they do sucker a lot.

I guess I am going to have to give this alot of thought as to where I should place it. I really did want it on the fence in the backyard but I don't think it gets "full sun" at all - it is always filtered. Thanks.