Usually, one or 3 squash plants require at least twice as much space as one of your little plots there... you really need to trellis those crawling vines.

Potatoes in your main garden area will also make you real unhappy, they get real buggy, they need mounding... but, if you really want to do potatoes in a city garden anyway, use the old tire trick on this page:

http://www.backwoodshome.com/articles2/sanders98.html

I have never done the tire trick myself (I hate growing potatoes, too much digging, though I love eating fresh potatoes) but I have heard it works real good.

One time I put cucumbers along a sunny side of the house, trellised about 5 feet up and they climbed by themselves the rest of the way to the roof. was kind of unintended that but that's what happened, we had cucumbers on the roof <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />