Is there any hope of growing it vertically

Not that I have ever found. Sprawl works better IME. The stems are multiple - 6-8 or more depending on variety - and they are also mostly hollow so they break over the supports on the cage and die.

The other issue is the over-crowding in any cage makes it much harder to track and treat for squash bugs.

Back when I tried Sq Foot I first tried 2 sq, upped it to 3 squares and it was still crowded so I upped it to 4 sq.

Dave

I just let mine grow on their own, They get about 24-30 inches tall and about 30 inches wide, So I set them 3-4 feet apart.

I have successfully grown vertical zucchini by using tall bamboo stakes instead of cages. The variety I grew (big box store) had only one main stem, so no trimming was necessary. Every 3-5" I secured the stem to the stake with a soft tie. The leaves I just let go where they wanted to, sometimes I trimmed off lower leaves as the plant grew. It did well for me all summer long, and took up about 1 1/2 - 2 square feet of space and got up to about 4 1/2 feet tall.

Then the vine borers discovered my garden and no more real zucchini since. :-(

Okay then it 4 squares it is. ;) Luckily I had left those squares empty for now (subconsciously preparing for sprawl perhaps?)

Now the pickle is that the cage is all around it now - and the main stem is in it full of fruit so i'm not sure I should pull it out - so we may end up with a combo situation with one stem going up and two sprawling...terrible idea? also this is called the learning curve right?

I stake my zucchini. Up to this point I've just grown the variety from the big box store with a single stem (going with black magic for the first time this summer since I needed new seeds). Like LilyD, I use soft/stretchy ties to tie the main stem to my stake ever few inches. Not always 100% successful because they often grow so fast that if you miss a few days they pull away from the stake and you can't really bend them back without breaking. They still take up about 2 feet of space this way, but I find it much easier to prune out the old leaves and they get much more air which helps with powdery leaf mildew that we seem to get by summer's end each year. Much more manageable when they are up off the ground.

Hmm - I'm wondering if I could stake the two stems that have escaped to the sides, and grow the main stem through the middle of the tomato cage?

Also - has anyone had trouble with disease with all that pruning? Seems like I'd be pruning a lot of leaves and wondering about all those open wounds....

Somewhere on the forums I remember seeing a thread about a wrapping method that supposedly worked well. If I can locate, I will link to it.

Here it is.

Here is a link that might be useful: upright zucchini

I only start pruning when it starts getting powdery leaf mildew. It always hits the lower leaves first, I try to never prune above the lowest fruit. I figure a cut leaf stem is better for the plant than holding onto a spore-producing diseased leaf. Then I treat the upper leaves. I battle PLM on my zucchini every year, but my plants last through the whole growing season because I'm able to get rid of the diseased leaves fairly easily. As long as the PLM stays under control, the plants will keep producing zucchini. I don't know that you'd need to prune if you have an overall healthy plant, nothing wrong with keeping the lower leaves as the plant grows up unless the leaves are diseased.