We have grown the type you use for birdhouses from transplants in the clay soil, up against a chain link fence, without amendments and very little fertilizer. They were a range of sizes from small to medium and from one vine I think we ended up with better than twenty gourds. We didn't pinch or pick very often though.. they were largely neglected. I wouldn't do it up against a chain link fence again though. The foliage is big and bushy and little gourds tend to sneak up on you and end up growing in the gaps of the fence. Rust is another issue.. of the fence, not the gourds lol.

The link below is bound to be a lot more helpful than I can be though, if you have not seen it previously:

Here is a link that might be useful: http://www.ncgourdsociety.org/growing.htm

I have some seeds if you would like them. Please email me. Still have the sunchokes too. Rosebush