Maybe that explains why no one in praetzel's community garden wants to grow vegetables that can be stored.

I think most vegetables that are poor keepers, summer squash included, are fine candidates for dehydration. A car parked in the summer sun is a very effective solar dehydrator, IME.

When I plan my garden for the next year (as I am starting to do today, as it happens), the first thing I do is to list all the crops that I know I can grow, plus maybe a few experiments, and my expected yields per square foot for each. Getting good yield data is difficult, but there are several cooperative extension websites online that have some data; with experience you can substitute your own data.

Next, I try to figure out how much of each crop we can use for the year. I break this down between what we will be consuming fresh per week on average for however many weeks we can stretch the season (and season extension is a VERY important issue - see Coleman's Four Season Harvest for ideas), and how much we will be consuming from storage each week on average for the rest of the year. I also make notes on my storage strategy for each crop. From the fresh and stored figures I determine the total amount that I need to grow for the year. Dividing by the yield per square foot determines how much garden space I need for each crop - as a first approximation, anyway. It gets more complicated for that for some crops. For example, for some vegetables like lettuce you should be able to grow two crops in the same space in succession, which halves the amount of space needed. For some crops you need to allow extra in case of poor germination, losses to pests or drought, etc. If you grow some crops in containers (as I do), then you need to come up with some sort of square footage figure for the containers.

Some of us don't have enough space to grow 100% of what we need. Thus, if you add up your required square footage and it is way more than what you have, then you are going to have to cut back and prioritize. As a general rule, my first priority is to cover as much as possible of my fresh vegetable needs in season, if the vegetables are not too difficult to grow and I'll be growing enough of them to make it worth my while. As for storage, things that are easy to store, or that will be difficult or expensive to get during the winter, are my next priorities. The relative dollar values of the crops are a consideration as well.

Once you have identified what you are going to grow and how many square feet to devote to each crop, then you can proceed to actually plan out your garden.

This is a lot of complicated work, but is the only way I know to avoid the "feast or famine" syndrome that is so typical amongst so many gardeners.