If what you mean is a "hoop House" then yes have grown vegetable crops on the coast of Crete, Greece.. Have grown bedding plants in Itality & Illinois, new mexico etc.
have also grown nursery stock in same here in Illinois

The high tunnel growers are probably producing a certain something with a much bigger margin than bedding plants. Of course if they are really serious about it they won't be high while working the crop.

Bigger Margin? How about 15 houses 30ftX100ft heasted for bedding plant/vegetable/hanging baskets etc... production

You didn't get the joke.

I'm sold on high tunnels for tomatoes and cucumbers. This is the first year I did not grow any outside tomatoes because experiences with tunnel grown tomatoes were far better. My harvest season started in May and just ended last week. You can't do that in your state or mine with outside tomatoes and that is just one of many reasons why I like the tunnels.

The high tunnels aren't as profitable with all crops but there appears to be no limit. Even fruits (strawberries, raspberries) and fruiting trees like cherry are being grown in them for various reasons. You don't need illegial crops to get payback in the first year bboy.

Oh My Gosh I was actually laughing out loud at a Garden Web thread -- thanks bboy!! I thought the OP was asking how to grow hedges or arbours that were shaped into tunnels!! Much more amusing though to envisage bboy's interpretation!!

New to the site! Anyone have experience with pit greenhouse?