You may need to add horizontal bars or rods to the U-channel post to have something for the plants to grab onto or to provide something for ties to wrap around without slipping downward. Another idea is to attach a piece of welded livestock panel to the post, either resting on ground or securely fastened to the post a few inches off the ground.

For ties you could thread them through holes drilled in the U-channel post. It's much easier to add horizontal bars or wire if you use 2 or more posts.

I was planning on doing 4 dowels around each plant & wrapping nylon netting around those. I hadnt thought about the ties slipping. Do do think if i wrapped the tie around the plant & then wrapped it around the little "j" type hook on the post it would work? If not there are holes in the posts that i could use. I would like to do a "wall" of zucs next year. Any ideas on how i could set that up? Maybe using the welded livestock fence? Hmmm now im going to be dreaming up all sorts of stuff lol

I was planning on doing 4 dowels around each plant & wrapping nylon netting around those. I hadnt thought about the ties slipping. Do do think if i wrapped the tie around the plant & then wrapped it around the little "j" type hook on the post it would work? If not there are holes in the posts that i could use. I would like to do a "wall" of zucs next year. Any ideas on how i could set that up? Maybe using the welded livestock fence? Hmmm now im going to be dreaming up all sorts of stuff lol

I'd need to see a picture of the post to be sure, but the "j" hook would seem to be adequate.

For a wall of zucchinis, a livestock panel would work fine, typically, they measure 50" tall and 16' long. If you use three 6' t-posts, you could have it all setup in about 10 or 15 minutes.

I am planning to set up 2 panels in parallel about 30" apart for my tomatoes.